### Question:
IntegerValue extends Value { @Override RealValue toRealValue () { return new RealValue (mValue); } IntegerValue(int value);   IntegerValue(String value); @Override String toString();  }### Answer:
@Test public void testToRealValue () { assertEquals ("-123", mNegativeValue.toRealValue ().toString ()); assertEquals ("0", mZeroValue.toRealValue ().toString ()); assertEquals ("123", mPositiveValue.toRealValue ().toString ()); }