### Question:
StringValue extends Value { @Override Value unequal (Value v) { return new BooleanValue (!mText.equals (v.toStringValue ().mText)); } StringValue(String text); @Override String toString();  }### Answer:
@Test public void testUnequal () { assertEquals ("false", mEmptyString.unequal (new StringValue ("")).toString ()); assertEquals ("false", mShortString.unequal (new StringValue ("a")).toString ()); assertEquals ("true", mShortString.unequal (mLongString).toString ()); }