@Test
public void testIsValidAddress() {

    assertTrue(AddressUtils.isValidAddress("Ab2fvZdmnM4HwDgVbdBrbTLz1wK5TcEyhU"));
    assertTrue(AddressUtils.isValidAddress("AK2nJJpJr6o664CWJKi1QRXjqeic2zRp8y"));
    assertFalse(AddressUtils.isValidAddress(""));
    assertFalse(AddressUtils.isValidAddress("0"));
    assertFalse(AddressUtils.isValidAddress("b2fvZdmnM4HwDgVbdBrbTLz1wK5TcEyhU"));
    assertFalse(AddressUtils.isValidAddress("AAb2fvZdmnM4HwDgVbdBrbTLz1wK5TcEyhU"));
    // If the address string is null, we don't want to say it is an invalid address because
    // there isn't even an address to be deemed invalid. Therefore expect NullPointerException.
    try {
        AddressUtils.isValidAddress(null);
    } catch (NullPointerException e) {
        return;
    }
    fail();
}