### Question:
MissingValueFormat extends Format { @Override public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) { return toAppendTo.append(obj == null ? "N/A" : d_format.format(obj)); } MissingValueFormat(NumberFormat format); @Override StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos); @Override Object parseObject(String source, ParsePosition pos);  }### Answer:
@Test public void testPreservedFunctionality() { assertEquals(d_integerInstance.format(-5.5), d_mvnf.format(-5.5)); assertEquals(d_integerInstance.format(10L), d_mvnf.format(10L)); }