@Test
public void testEqualChars() {

    assertTrue(offByOne.equalChars('a', 'b'));
    assertTrue(offByOne.equalChars('r', 'q'));
    assertFalse(offByOne.equalChars('a', 'e'));
    assertFalse(offByOne.equalChars('z', 'a'));
    assertFalse(offByOne.equalChars('a', 'a'));
}