### Question:
IntegerIdentifier implements IIdentifier, Serializable { public boolean equals(Object rhs) { boolean rc = false; if (rhs != null && rhs.getClass().equals(getClass())) { rc = ((IntegerIdentifier)rhs).toString().equals(toString()); } return rc; } IntegerIdentifier(int value); boolean equals(Object rhs); synchronized int hashCode(); String toString(); void setString(String value);  }### Answer:
@Test public void testEquals() { IntegerIdentifier uid1 = new IntegerIdentifier(1); IntegerIdentifier uid2 = new IntegerIdentifier(1); IntegerIdentifier uid3 = new IntegerIdentifier(2); IntegerIdentifier uid4 = new IntegerIdentifier(1) { private static final long serialVersionUID = 1L; }; new EqualsTester(uid1, uid2, uid3, uid4); }