@Test
public void testDiff() {

    IAtomType element1 = mock(IAtomType.class);
    IAtomType element2 = mock(IAtomType.class);
    when(element1.getHybridization()).thenReturn(PLANAR3);
    when(element2.getHybridization()).thenReturn(SP3);
    String result = AtomTypeDiff.diff(element1, element2);
    Assert.assertNotNull(result);
    Assert.assertNotSame(0, result.length());
    assertContains(result, "AtomTypeDiff");
    assertContains(result, "PLANAR3/SP3");
}