### Question:
StringKey implements Key<T> { @Override public int hashCode() { return Objects.hash(keyString); } @SuppressWarnings("WeakerAccess") // Used by generated Entities  StringKey(final String keyString); @Override byte[] toBytes(); @Override boolean equals(final Object o); @Override int hashCode(); @Override String toString(); @Override int compareTo(Key otherKey);  }### Answer:
@Test public void testHashCodeReturnsDifferentValuesWhenKeysAreNotEqual() { final Key<Entity> a = new StringKey<>("hello"); final Key<Entity> b = new StringKey<>("world"); assertNotEquals(a.hashCode(), b.hashCode()); }
@Test public void testHashCodeReturnsEqualValuesWhenKeysAreEqual() { final Key<Entity> a = new StringKey<>("goodbye"); final Key<Entity> b = new StringKey<>("goodbye"); assertEquals(a.hashCode(), b.hashCode()); }