### Question:
IntegerValue extends Value { IntegerValue (int value) { mValue = Integer.toString (value); } IntegerValue(int value);   IntegerValue(String value); @Override String toString();  }### Answer:
@Test public void testIntegerValue () { assertEquals ("123", new IntegerValue (123).toString ()); assertEquals ("0", new IntegerValue (0).toString ()); assertEquals ("-123", new IntegerValue (-123).toString ()); assertEquals ("123", new IntegerValue ("123").toString ()); assertEquals ("0", new IntegerValue ("0").toString ()); assertEquals ("-123", new IntegerValue ("-123").toString ()); assertEquals ("0123", new IntegerValue ("0123").toString ()); }