### Question:
ClassPair implements Comparable<ClassPair> { @Override public boolean equals(Object obj) { if (obj == null || !(obj instanceof ClassPair)){ return false; } ClassPair otherPair = (ClassPair) obj; if(! otherPair.class1.equals(this.class1) && !otherPair.class1.equals(this.class2)){ return false; } if(! otherPair.class2.equals(this.class1) && !otherPair.class2.equals(this.class2)){ return false; } return true; } ClassPair(String class1, String class2, int score1, int score2); @Override boolean equals(Object obj); @Override int compareTo(ClassPair otherPair); String getClass1(); String getClass2(); int getCallScore1(); int getCallScore2(); int getTotalScore(); int getNumberOfBranchesInClass1(); int getNumberOfBranchesInClass2(); void addTonumberOfBranches(String className, int value); List<Integer> getListOfObjectivesValue();  }### Answer:
@Test public void testEqualsMethod(){ Assert.assertFalse(classPair.equals(null)); Assert.assertFalse(classPair.equals(new String())); ClassPair classPair2 = new ClassPair("eu.stamp.example.classx",class2,1, 5); Assert.assertFalse(classPair.equals(classPair2)); classPair2 = new ClassPair(class1, "eu.stamp.example.classx",1, 5); Assert.assertFalse(classPair.equals(classPair2)); classPair2 = new ClassPair(class1,class2,0, 0); Assert.assertTrue(classPair.equals(classPair2)); }