### Question:
MutableInt extends AbstractMutableInteger <MutableInt> { public MutableInt (@Nonnull final Number aValue) { this (aValue.intValue ()); } MutableInt(@Nonnull final Number aValue);  MutableInt(final int nValue); @Override int intValue(); @Override float floatValue(); @Override double doubleValue(); @Override long longValue(); int inc(); int inc(final int nDelta); int inc(@Nonnull final Number aDelta); int dec(); int dec(final int nDelta); int dec(@Nonnull final Number aDelta); int divide(final int nDivisor); int divide(@Nonnull final Number aDivisor); int multiply(final int nMultiplicand); int multiply(@Nonnull final Number aMultiplicand); @Nonnull EChange set(final int nValue); @Nonnull EChange set(@Nonnull final Number aValue); boolean is0(); boolean isLT0(); boolean isLE0(); boolean isGT0(); boolean isGE0(); boolean isEven(); int compareTo(@Nonnull final MutableInt rhs); @Nonnull MutableInt getClone(); @Override boolean equals(final Object o); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testMutableInt () { final MutableInt x = new MutableInt (0); assertEquals (0, x.intValue ()); assertEquals (Integer.valueOf (0), x.getAsInteger ()); assertFalse (x.isNot0 ()); assertTrue (x.is0 ()); x.inc (); assertEquals (1, x.intValue ()); assertNotEquals (x.hashCode (), x.intValue ()); x.inc (5); assertEquals (6, x.intValue ()); assertNotEquals (x.hashCode (), x.intValue ()); x.inc (-2); assertEquals (4, x.intValue ()); assertNotEquals (x.hashCode (), x.intValue ()); x.dec (); assertEquals (3, x.intValue ()); assertFalse (x.isEven ()); assertNotEquals (x.hashCode (), x.intValue ()); x.dec (5); assertEquals (-2, x.intValue ()); assertTrue (x.isNot0 ()); assertFalse (x.is0 ()); assertTrue (x.isEven ()); assertNotEquals (x.hashCode (), x.intValue ()); assertTrue (x.set (4711).isChanged ()); assertFalse (x.set (4711).isChanged ()); assertFalse (x.isEven ()); assertEquals (4711, x.intValue ()); assertEquals (-1, new MutableInt (4).compareTo (new MutableInt (5))); assertEquals (0, new MutableInt (5).compareTo (new MutableInt (5))); assertEquals (+1, new MutableInt (6).compareTo (new MutableInt (5))); assertNotNull (x.toString ()); assertTrue (x.toString ().contains (Integer.toString (x.intValue ()))); x.set (-1); assertFalse (x.isGT0 ()); x.set (0); assertFalse (x.isGT0 ()); x.set (1); assertTrue (x.isGT0 ()); CommonsTestHelper.testDefaultImplementationWithEqualContentObject (new MutableInt (-7), new MutableInt (-7)); CommonsTestHelper.testDefaultImplementationWithDifferentContentObject (new MutableInt (6), new MutableInt (7)); CommonsTestHelper.testGetClone (new MutableInt (Integer.MAX_VALUE)); }