From 5150d9323012b2457e95fb877b93b8c718368ffb Mon Sep 17 00:00:00 2001
From: XenoAmess <xenoamess@gmail.com>
Date: Sat, 23 Apr 2022 08:09:42 +0800
Subject: [PATCH] fix code smells. (#104)

* add missing @Override s.

* array declaration beautify.

* loop beautify.

* fix error in javadoc.

* replace addAll() to constructor.

* use StringBuilder insteadof +=

* StringBuilder chain append.

* add cache to travis. add openjdk8 to travis.

* add javadoc-plugin to build in pom.

* "static public" to "public static"
---
 .travis.yml                                   |  6 +++
 pom.xml                                       | 38 +++++++++++++++-
 src/main/java/org/yinwang/pysonar/$.java      | 15 +++----
 .../java/org/yinwang/pysonar/Analyzer.java    | 32 ++++++-------
 .../java/org/yinwang/pysonar/Binding.java     |  1 +
 .../java/org/yinwang/pysonar/Outliner.java    | 14 +++++-
 src/main/java/org/yinwang/pysonar/Parser.java |  6 +--
 src/main/java/org/yinwang/pysonar/Stats.java  |  2 +-
 .../org/yinwang/pysonar/ast/FunctionDef.java  |  4 +-
 .../java/org/yinwang/pysonar/demos/Demo.java  |  3 +-
 .../java/org/yinwang/pysonar/demos/Style.java |  1 +
 .../yinwang/pysonar/demos/StyleApplier.java   | 16 +++----
 .../pysonar/hash/FunTypeEqualFunction.java    |  1 +
 .../pysonar/hash/GenericEqualFunction.java    |  1 +
 .../org/yinwang/pysonar/hash/MyHashMap.java   | 45 +++++++++++++++++--
 .../org/yinwang/pysonar/hash/MyHashSet.java   |  7 +++
 .../org/yinwang/pysonar/types/UnionType.java  |  6 +--
 17 files changed, 147 insertions(+), 51 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index bd91a952..b136692c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,9 @@
 language: java
+
+cache:
+  directories:
+    - "$HOME/.m2"
+
 jdk:
+  - openjdk8
   - oraclejdk12
diff --git a/pom.xml b/pom.xml
index ea38f056..9a89999c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -13,8 +13,11 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.build.outputEncoding>UTF-8</project.build.outputEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
         <maven-compiler-plugin.version>3.1</maven-compiler-plugin.version>
         <maven-shade-plugin.version>2.1</maven-shade-plugin.version>
+        <maven-javadoc-plugin.version>3.1.1</maven-javadoc-plugin.version>
         <gson-version>2.2.4</gson-version>
         <jackson-version>2.10.0</jackson-version>
     </properties>
@@ -85,8 +88,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${maven-compiler-plugin.version}</version>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -123,6 +126,37 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>${maven-javadoc-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <quiet>true</quiet>
+                    <encoding>utf-8</encoding>
+                    <docencoding>utf-8</docencoding>
+                    <notimestamp>true</notimestamp>
+                    <links>
+                        <link>https://docs.oracle.com/javase/8/docs/api/</link>
+                        <link>http://docs.oracle.com/javaee/6/api/</link>
+                    </links>
+                    <archive>
+                        <manifest>
+                            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
+                            <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
+                        </manifest>
+                    </archive>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>create-javadoc-jar</id>
+                        <goals>
+                            <goal>javadoc</goal>
+                            <goal>jar</goal>
+                        </goals>
+                        <phase>package</phase>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
diff --git a/src/main/java/org/yinwang/pysonar/$.java b/src/main/java/org/yinwang/pysonar/$.java
index e8a6cf18..a0e0fcfe 100644
--- a/src/main/java/org/yinwang/pysonar/$.java
+++ b/src/main/java/org/yinwang/pysonar/$.java
@@ -130,8 +130,7 @@ public static String arrayToString(@NotNull Collection<String> strings) {
 
     @NotNull
     public static String arrayToSortedStringSet(Collection<String> strings) {
-        Set<String> sorter = new TreeSet<>();
-        sorter.addAll(strings);
+        Set<String> sorter = new TreeSet<>(strings);
         return arrayToString(sorter);
     }
 
@@ -270,7 +269,7 @@ public static String getContentHash(byte[] fileContents) {
 
         algorithm.reset();
         algorithm.update(fileContents);
-        byte messageDigest[] = algorithm.digest();
+        byte[] messageDigest = algorithm.digest();
         StringBuilder sb = new StringBuilder();
         for (byte aMessageDigest : messageDigest) {
             sb.append(String.format("%02x", 0xFF & aMessageDigest));
@@ -279,7 +278,7 @@ public static String getContentHash(byte[] fileContents) {
     }
 
 
-    static public String escapeQname(@NotNull String s) {
+    public static String escapeQname(@NotNull String s) {
         return s.replaceAll("[.&@%-]", "_");
     }
 
@@ -300,7 +299,7 @@ public static Collection<String> toStringCollection(@NotNull Collection<Integer>
 
 
     @NotNull
-    static public String joinWithSep(@NotNull Collection<String> ls, String sep, @Nullable String start,
+    public static String joinWithSep(@NotNull Collection<String> ls, String sep, @Nullable String start,
                                      @Nullable String end)
     {
         StringBuilder sb = new StringBuilder();
@@ -581,11 +580,11 @@ public static String getGCStats() {
         StringBuilder sb = new StringBuilder();
 
         sb.append(banner("memory stats"));
-        sb.append("\n- total collections: " + totalGC);
-        sb.append("\n- total collection time: " + formatTime(gcTime));
+        sb.append("\n- total collections: ").append(totalGC);
+        sb.append("\n- total collection time: ").append(formatTime(gcTime));
 
         Runtime runtime = Runtime.getRuntime();
-        sb.append("\n- total memory: " + $.printMem(runtime.totalMemory()));
+        sb.append("\n- total memory: ").append($.printMem(runtime.totalMemory()));
 
         return sb.toString();
     }
diff --git a/src/main/java/org/yinwang/pysonar/Analyzer.java b/src/main/java/org/yinwang/pysonar/Analyzer.java
index e56d9354..ebcf8a44 100644
--- a/src/main/java/org/yinwang/pysonar/Analyzer.java
+++ b/src/main/java/org/yinwang/pysonar/Analyzer.java
@@ -337,14 +337,14 @@ public String makeQname(@NotNull List<Name> names) {
             return "";
         }
 
-        String ret = "";
+        StringBuilder ret = new StringBuilder();
 
         for (int i = 0; i < names.size() - 1; i++) {
-            ret += names.get(i).id + ".";
+            ret.append(names.get(i).id).append(".");
         }
 
-        ret += names.get(names.size() - 1).id;
-        return ret;
+        ret.append(names.get(names.size() - 1).id);
+        return ret.toString();
     }
 
 
@@ -563,13 +563,13 @@ public void applyUncalled() {
     @NotNull
     public String getAnalysisSummary() {
         StringBuilder sb = new StringBuilder();
-        sb.append("\n" + $.banner("analysis summary"));
+        sb.append("\n").append($.banner("analysis summary"));
 
         String duration = $.formatTime(System.currentTimeMillis() - stats.getInt("startTime"));
-        sb.append("\n- total time: " + duration);
-        sb.append("\n- modules loaded: " + loadedFiles.size());
-        sb.append("\n- semantic problems: " + semanticErrors.size());
-        sb.append("\n- failed to parse: " + failedToParse.size());
+        sb.append("\n- total time: ").append(duration);
+        sb.append("\n- modules loaded: ").append(loadedFiles.size());
+        sb.append("\n- semantic problems: ").append(semanticErrors.size());
+        sb.append("\n- failed to parse: ").append(failedToParse.size());
 
         // calculate number of defs, refs, xrefs
         int nDef = 0, nXRef = 0;
@@ -578,16 +578,16 @@ public String getAnalysisSummary() {
             nXRef += b.refs.size();
         }
 
-        sb.append("\n- number of definitions: " + nDef);
-        sb.append("\n- number of cross references: " + nXRef);
-        sb.append("\n- number of references: " + references.size());
+        sb.append("\n- number of definitions: ").append(nDef);
+        sb.append("\n- number of cross references: ").append(nXRef);
+        sb.append("\n- number of references: ").append(references.size());
 
         long nResolved = resolved.size();
         long nUnresolved = unresolved.size();
-        sb.append("\n- resolved names: " + nResolved);
-        sb.append("\n- unresolved names: " + nUnresolved);
-        sb.append("\n- name resolve rate: " + $.percent(nResolved, nResolved + nUnresolved));
-        sb.append("\n" + $.getGCStats());
+        sb.append("\n- resolved names: ").append(nResolved);
+        sb.append("\n- unresolved names: ").append(nUnresolved);
+        sb.append("\n- name resolve rate: ").append($.percent(nResolved, nResolved + nUnresolved));
+        sb.append("\n").append($.getGCStats());
 
         return sb.toString();
     }
diff --git a/src/main/java/org/yinwang/pysonar/Binding.java b/src/main/java/org/yinwang/pysonar/Binding.java
index c470d8cb..cdbfc6a8 100644
--- a/src/main/java/org/yinwang/pysonar/Binding.java
+++ b/src/main/java/org/yinwang/pysonar/Binding.java
@@ -211,6 +211,7 @@ public boolean isURL() {
     /**
      * Bindings can be sorted by their location for outlining purposes.
      */
+    @Override
     public int compareTo(@NotNull Object o) {
         if (start == ((Binding) o).start) {
             return end - ((Binding) o).end;
diff --git a/src/main/java/org/yinwang/pysonar/Outliner.java b/src/main/java/org/yinwang/pysonar/Outliner.java
index 0043324d..b1c4bfdb 100644
--- a/src/main/java/org/yinwang/pysonar/Outliner.java
+++ b/src/main/java/org/yinwang/pysonar/Outliner.java
@@ -150,26 +150,31 @@ public Branch(String qname, int start, Binding.Kind kind) {
         }
 
 
+        @Override
         public boolean isLeaf() {
             return false;
         }
 
 
+        @Override
         public boolean isBranch() {
             return true;
         }
 
 
+        @Override
         public boolean hasChildren() {
             return children != null && !children.isEmpty();
         }
 
 
+        @Override
         public List<Entry> getChildren() {
             return children;
         }
 
 
+        @Override
         public void setChildren(List<Entry> children) {
             this.children = children;
         }
@@ -180,11 +185,13 @@ public void setChildren(List<Entry> children) {
      * An entry with no children.
      */
     public static class Leaf extends Entry {
+        @Override
         public boolean isLeaf() {
             return true;
         }
 
 
+        @Override
         public boolean isBranch() {
             return false;
         }
@@ -199,17 +206,20 @@ public Leaf(String qname, int start, Binding.Kind kind) {
         }
 
 
+        @Override
         public boolean hasChildren() {
             return false;
         }
 
 
+        @Override
         @NotNull
         public List<Entry> getChildren() {
             return new ArrayList<>();
         }
 
 
+        @Override
         public void setChildren(List<Entry> children) {
             throw new UnsupportedOperationException("Leaf nodes cannot have children.");
         }
@@ -219,8 +229,8 @@ public void setChildren(List<Entry> children) {
     /**
      * Create an outline for a file in the index.
      *
-     * @param scope the file scope
-     * @param path  the file for which to build the outline
+     * @param idx     the file scope
+     * @param abspath the file for which to build the outline
      * @return a list of entries constituting the file outline.
      * Returns an empty list if the analyzer hasn't analyzed that path.
      */
diff --git a/src/main/java/org/yinwang/pysonar/Parser.java b/src/main/java/org/yinwang/pysonar/Parser.java
index 8c284e15..444debd4 100644
--- a/src/main/java/org/yinwang/pysonar/Parser.java
+++ b/src/main/java/org/yinwang/pysonar/Parser.java
@@ -894,7 +894,7 @@ List<Name> segmentQname(@NotNull String qname, int start, boolean hasLoc) {
         List<Name> result = new ArrayList<>();
 
         for (int i = 0; i < qname.length(); i++) {
-            String name = "";
+            StringBuilder name = new StringBuilder();
             while (Character.isSpaceChar(qname.charAt(i))) {
                 i++;
             }
@@ -905,14 +905,14 @@ List<Name> segmentQname(@NotNull String qname, int start, boolean hasLoc) {
                             qname.charAt(i) == '*') &&
                     qname.charAt(i) != '.')
             {
-                name += qname.charAt(i);
+                name.append(qname.charAt(i));
                 i++;
             }
 
             int nameStop = i;
             int nstart = hasLoc ? start + nameStart : -1;
             int nstop = hasLoc ? start + nameStop : -1;
-            result.add(new Name(name, file, nstart, nstop, 0, 0));
+            result.add(new Name(name.toString(), file, nstart, nstop, 0, 0));
         }
 
         return result;
diff --git a/src/main/java/org/yinwang/pysonar/Stats.java b/src/main/java/org/yinwang/pysonar/Stats.java
index d18343fc..7e1022a7 100644
--- a/src/main/java/org/yinwang/pysonar/Stats.java
+++ b/src/main/java/org/yinwang/pysonar/Stats.java
@@ -43,7 +43,7 @@ public String print() {
         StringBuilder sb = new StringBuilder();
 
         for (Map.Entry<String, Object> e : contents.entrySet()) {
-            sb.append("\n- " + e.getKey() + ": " + e.getValue());
+            sb.append("\n- ").append(e.getKey()).append(": ").append(e.getValue());
         }
 
         return sb.toString();
diff --git a/src/main/java/org/yinwang/pysonar/ast/FunctionDef.java b/src/main/java/org/yinwang/pysonar/ast/FunctionDef.java
index 233aa7e3..b729d4ee 100644
--- a/src/main/java/org/yinwang/pysonar/ast/FunctionDef.java
+++ b/src/main/java/org/yinwang/pysonar/ast/FunctionDef.java
@@ -61,14 +61,14 @@ public String getArgumentExpr() {
                 argExpr.append(", ");
             }
             first = false;
-            argExpr.append("*" + vararg.toDisplay());
+            argExpr.append("*").append(vararg.toDisplay());
         }
 
         if (kwarg != null) {
             if (!first) {
                 argExpr.append(", ");
             }
-            argExpr.append("**" + kwarg.toDisplay());
+            argExpr.append("**").append(kwarg.toDisplay());
         }
 
         argExpr.append(")");
diff --git a/src/main/java/org/yinwang/pysonar/demos/Demo.java b/src/main/java/org/yinwang/pysonar/demos/Demo.java
index 4450a4ae..95b044d0 100644
--- a/src/main/java/org/yinwang/pysonar/demos/Demo.java
+++ b/src/main/java/org/yinwang/pysonar/demos/Demo.java
@@ -108,8 +108,7 @@ private String markup(String path) {
             return "";
         }
 
-        List<Style> styles = new ArrayList<>();
-        styles.addAll(linker.getStyles(path));
+        List<Style> styles = new ArrayList<>(linker.getStyles(path));
 
         String styledSource = new StyleApplier(path, source, styles).apply();
         String outline = new HtmlOutline(analyzer).generate(path);
diff --git a/src/main/java/org/yinwang/pysonar/demos/Style.java b/src/main/java/org/yinwang/pysonar/demos/Style.java
index 7971633d..24617026 100644
--- a/src/main/java/org/yinwang/pysonar/demos/Style.java
+++ b/src/main/java/org/yinwang/pysonar/demos/Style.java
@@ -71,6 +71,7 @@ public boolean equals(Object o) {
     }
 
 
+    @Override
     public int compareTo(@NotNull Style other) {
         if (this.equals(other)) {
             return 0;
diff --git a/src/main/java/org/yinwang/pysonar/demos/StyleApplier.java b/src/main/java/org/yinwang/pysonar/demos/StyleApplier.java
index b64ae991..a8e2d9c3 100644
--- a/src/main/java/org/yinwang/pysonar/demos/StyleApplier.java
+++ b/src/main/java/org/yinwang/pysonar/demos/StyleApplier.java
@@ -67,16 +67,16 @@ void insert() {
             if (Analyzer.self.hasOption("debug")) {
                 switch (style.type) {
                     case ANCHOR:
-                        buffer.append("<a name='" + style.url + "'");
-                        buffer.append(", id ='" + style.id + "'");
+                        buffer.append("<a name='").append(style.url).append("'");
+                        buffer.append(", id ='").append(style.id).append("'");
                         if (style.highlight != null && !style.highlight.isEmpty()) {
                             String ids = $.joinWithSep(style.highlight, "\",\"", "\"", "\"");
                             buffer.append(", onmouseover='highlight(").append(ids).append(")'");
                         }
                         break;
                     case LINK:
-                        buffer.append("<a href='" + style.url + "'");
-                        buffer.append(", id ='" + style.id + "'");
+                        buffer.append("<a href='").append(style.url).append("'");
+                        buffer.append(", id ='").append(style.id).append("'");
                         if (style.highlight != null && !style.highlight.isEmpty()) {
                             String ids = $.joinWithSep(style.highlight, "\",\"", "\"", "\"");
                             buffer.append(", onmouseover='highlight(").append(ids).append(")'");
@@ -90,12 +90,12 @@ void insert() {
             } else {
                 switch (style.type) {
                     case ANCHOR:
-                        buffer.append("<a name='" + style.url + "'");
-                        buffer.append(", xid ='" + style.id + "'");
+                        buffer.append("<a name='").append(style.url).append("'");
+                        buffer.append(", xid ='").append(style.id).append("'");
                         break;
                     case LINK:
-                        buffer.append("<a href='" + style.url + "'");
-                        buffer.append(", xid ='" + style.id + "'");
+                        buffer.append("<a href='").append(style.url).append("'");
+                        buffer.append(", xid ='").append(style.id).append("'");
                         break;
                     default:
                         buffer.append("<span class='");
diff --git a/src/main/java/org/yinwang/pysonar/hash/FunTypeEqualFunction.java b/src/main/java/org/yinwang/pysonar/hash/FunTypeEqualFunction.java
index bf0e2b87..2702e58a 100644
--- a/src/main/java/org/yinwang/pysonar/hash/FunTypeEqualFunction.java
+++ b/src/main/java/org/yinwang/pysonar/hash/FunTypeEqualFunction.java
@@ -5,6 +5,7 @@
 
 public class FunTypeEqualFunction extends EqualFunction {
 
+    @Override
     public boolean equals(Object x, Object y) {
         if (x instanceof FunType && y instanceof FunType) {
             FunType xx = (FunType) x;
diff --git a/src/main/java/org/yinwang/pysonar/hash/GenericEqualFunction.java b/src/main/java/org/yinwang/pysonar/hash/GenericEqualFunction.java
index 389cb83e..9cd2326e 100644
--- a/src/main/java/org/yinwang/pysonar/hash/GenericEqualFunction.java
+++ b/src/main/java/org/yinwang/pysonar/hash/GenericEqualFunction.java
@@ -2,6 +2,7 @@
 
 
 public class GenericEqualFunction extends EqualFunction {
+    @Override
     public boolean equals(Object x, Object y) {
         return x.equals(y);
     }
diff --git a/src/main/java/org/yinwang/pysonar/hash/MyHashMap.java b/src/main/java/org/yinwang/pysonar/hash/MyHashMap.java
index 5192b272..3f91ccbf 100644
--- a/src/main/java/org/yinwang/pysonar/hash/MyHashMap.java
+++ b/src/main/java/org/yinwang/pysonar/hash/MyHashMap.java
@@ -97,22 +97,26 @@ static int slot(int h, int length) {
     }
 
 
+    @Override
     public int size() {
         return size;
     }
 
 
+    @Override
     public boolean isEmpty() {
         return size == 0;
     }
 
 
+    @Override
     public V get(@NotNull Object key) {
         Entry<K, V> entry = getEntry(key);
         return entry == null ? null : entry.getValue();
     }
 
 
+    @Override
     public boolean containsKey(@NotNull Object key) {
         return getEntry(key) != null;
     }
@@ -136,6 +140,7 @@ final Entry<K, V> getEntry(@NotNull Object key) {
     }
 
 
+    @Override
     public V put(@NotNull K key, V value) {
         if (isEmpty()) {
             initTable(threshold);
@@ -176,6 +181,7 @@ void resize(int size) {
     }
 
 
+    @Override
     public void putAll(Map<? extends K, ? extends V> m) {
         for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) {
             put(e.getKey(), e.getValue());
@@ -183,6 +189,7 @@ public void putAll(Map<? extends K, ? extends V> m) {
     }
 
 
+    @Override
     public V remove(Object key) {
         Entry<K, V> e = removeEntry(key);
         return e == null ? null : e.value;
@@ -245,6 +252,7 @@ Entry<K, V> removeMapping(Map.Entry entry) {
     }
 
 
+    @Override
     public void clear() {
         modCount++;
         Arrays.fill(table, null);
@@ -252,14 +260,15 @@ public void clear() {
     }
 
 
+    @Override
     public boolean containsValue(Object value) {
         if (value == null) {
             return containsNullValue();
         }
 
         Entry[] tab = table;
-        for (int i = 0; i < tab.length; i++) {
-            for (Entry e = tab[i]; e != null; e = e.next) {
+        for (Entry entry : tab) {
+            for (Entry e = entry; e != null; e = e.next) {
                 if (equalFunction.equals(value, e.value)) {
                     return true;
                 }
@@ -271,8 +280,8 @@ public boolean containsValue(Object value) {
 
     private boolean containsNullValue() {
         Entry[] tab = table;
-        for (int i = 0; i < tab.length; i++) {
-            for (Entry e = tab[i]; e != null; e = e.next) {
+        for (Entry entry : tab) {
+            for (Entry e = entry; e != null; e = e.next) {
                 if (e.value == null) {
                     return true;
                 }
@@ -297,16 +306,19 @@ static class Entry<K, V> implements Map.Entry<K, V> {
         }
 
 
+        @Override
         public final K getKey() {
             return key;
         }
 
 
+        @Override
         public final V getValue() {
             return value;
         }
 
 
+        @Override
         public final V setValue(V newValue) {
             V oldValue = value;
             value = newValue;
@@ -314,6 +326,7 @@ public final V setValue(V newValue) {
         }
 
 
+        @Override
         public final boolean equals(Object o) {
             if (!(o instanceof Map.Entry)) {
                 return false;
@@ -332,11 +345,13 @@ public final boolean equals(Object o) {
         }
 
 
+        @Override
         public final int hashCode() {
             return Objects.hashCode(getKey()) ^ Objects.hashCode(getValue());
         }
 
 
+        @Override
         public final String toString() {
             return getKey() + "=" + getValue();
         }
@@ -383,6 +398,7 @@ private abstract class HashIterator<E> implements Iterator<E> {
         }
 
 
+        @Override
         public final boolean hasNext() {
             return next != null;
         }
@@ -413,6 +429,7 @@ final Entry<K, V> nextEntry() {
         }
 
 
+        @Override
         public void remove() {
             if (current == null) {
                 throw new IllegalStateException();
@@ -428,24 +445,28 @@ public void remove() {
     }
 
     private final class ValueIterator extends HashIterator<V> {
+        @Override
         public V next() {
             return nextEntry().value;
         }
     }
 
     private final class KeyIterator extends HashIterator<K> {
+        @Override
         public K next() {
             return nextEntry().getKey();
         }
     }
 
     private final class EntryIterator extends HashIterator<Map.Entry<K, V>> {
+        @Override
         public Map.Entry<K, V> next() {
             return nextEntry();
         }
     }
 
 
+    @Override
     public Set<K> keySet() {
         if (keySet == null) {
             keySet = new KeySet();
@@ -455,32 +476,38 @@ public Set<K> keySet() {
 
 
     private final class KeySet extends AbstractSet<K> {
+        @Override
         public Iterator<K> iterator() {
             return new KeyIterator();
         }
 
 
+        @Override
         public int size() {
             return size;
         }
 
 
+        @Override
         public boolean contains(Object o) {
             return containsKey(o);
         }
 
 
+        @Override
         public boolean remove(Object o) {
             return MyHashMap.this.removeEntry(o) != null;
         }
 
 
+        @Override
         public void clear() {
             MyHashMap.this.clear();
         }
     }
 
 
+    @Override
     public Collection<V> values() {
         if (values == null) {
             values = new Values();
@@ -490,27 +517,32 @@ public Collection<V> values() {
 
 
     private final class Values extends AbstractCollection<V> {
+        @Override
         public Iterator<V> iterator() {
             return new ValueIterator();
         }
 
 
+        @Override
         public int size() {
             return size;
         }
 
 
+        @Override
         public boolean contains(Object o) {
             return containsValue(o);
         }
 
 
+        @Override
         public void clear() {
             MyHashMap.this.clear();
         }
     }
 
 
+    @Override
     public Set<Map.Entry<K, V>> entrySet() {
         if (entrySet == null) {
             entrySet = new EntrySet();
@@ -520,11 +552,13 @@ public Set<Map.Entry<K, V>> entrySet() {
 
 
     private final class EntrySet extends AbstractSet<Map.Entry<K, V>> {
+        @Override
         public Iterator<Map.Entry<K, V>> iterator() {
             return new EntryIterator();
         }
 
 
+        @Override
         public boolean contains(Object o) {
             if (!(o instanceof Map.Entry)) {
                 return false;
@@ -535,6 +569,7 @@ public boolean contains(Object o) {
         }
 
 
+        @Override
         public boolean remove(Object o) {
             if (isEmpty() || !(o instanceof Map.Entry)) {
                 return false;
@@ -543,11 +578,13 @@ public boolean remove(Object o) {
         }
 
 
+        @Override
         public int size() {
             return size;
         }
 
 
+        @Override
         public void clear() {
             MyHashMap.this.clear();
         }
diff --git a/src/main/java/org/yinwang/pysonar/hash/MyHashSet.java b/src/main/java/org/yinwang/pysonar/hash/MyHashSet.java
index 8b932cf0..18975106 100644
--- a/src/main/java/org/yinwang/pysonar/hash/MyHashSet.java
+++ b/src/main/java/org/yinwang/pysonar/hash/MyHashSet.java
@@ -40,36 +40,43 @@ public MyHashSet() {
     }
 
 
+    @Override
     public Iterator<E> iterator() {
         return map.keySet().iterator();
     }
 
 
+    @Override
     public int size() {
         return map.size();
     }
 
 
+    @Override
     public boolean isEmpty() {
         return map.isEmpty();
     }
 
 
+    @Override
     public boolean contains(Object o) {
         return map.containsKey(o);
     }
 
 
+    @Override
     public boolean add(E e) {
         return map.put(e, PRESENT) == null;
     }
 
 
+    @Override
     public boolean remove(Object o) {
         return map.remove(o) == PRESENT;
     }
 
 
+    @Override
     public void clear() {
         map.clear();
     }
diff --git a/src/main/java/org/yinwang/pysonar/types/UnionType.java b/src/main/java/org/yinwang/pysonar/types/UnionType.java
index 3459b7aa..902bb8c6 100644
--- a/src/main/java/org/yinwang/pysonar/types/UnionType.java
+++ b/src/main/java/org/yinwang/pysonar/types/UnionType.java
@@ -37,7 +37,7 @@ public boolean isEmpty() {
     /**
      * Returns true if t1 == t2 or t1 is a union type that contains t2.
      */
-    static public boolean contains(Type t1, Type t2) {
+    public static boolean contains(Type t1, Type t2) {
         if (t1 instanceof UnionType) {
             return ((UnionType) t1).contains(t2);
         } else {
@@ -46,7 +46,7 @@ static public boolean contains(Type t1, Type t2) {
     }
 
 
-    static public Type remove(Type t1, Type t2) {
+    public static Type remove(Type t1, Type t2) {
         if (t1 instanceof UnionType) {
             Set<Type> types = new HashSet<>(((UnionType) t1).types);
             types.remove(t2);
@@ -60,7 +60,7 @@ static public Type remove(Type t1, Type t2) {
 
 
     @NotNull
-    static public Type newUnion(@NotNull Collection<Type> types) {
+    public static Type newUnion(@NotNull Collection<Type> types) {
         Type t = Types.UNKNOWN;
         for (Type nt : types) {
             t = union(t, nt);