### Question:
EmailValidationImpl extends AbstractValidation<String > implements EmailValidation { @Override protected void validate(ValidationContext<String> context) { validateNotNull(context); validateMail(context); }    }### Answer:
@Test public void somebody_at_gmail_adress_is_valid() { assertTrue(validationToTest.validate("somebody@gmail.com").isValid()); }
@Test public void null_is_invalid() { assertFalse(validationToTest.validate((String)null).isValid()); }
@Test public void empty_is_invalid() { assertFalse(validationToTest.validate("").isValid()); }