    @Test
    public final void shouldAddDefaultMessageIfValidationFailAndThereIsAlreadyMessageAssignedToOtherField() {

        // given
        Map<String, ErrorMessage> errors = Maps.newHashMap();
        errors.put("another" + FIELD_NAME, new ErrorMessage(CUSTOM_MSG));
        stubFieldHookDef(false, errors);

        // when
        boolean isValid = customValidator.call(entity, oldValue, newValue);

        // then
        assertFalse(isValid);
        verify(fieldHookDef, times(1)).call(entity, oldValue, newValue);
        ArgumentCaptor<String> argCaptor = ArgumentCaptor.forClass(String.class);
        verify(entity, times(1)).addError(Mockito.eq(fieldDefinition), argCaptor.capture(), Mockito.<String> anyVararg());
        assertEquals(DEFAULT_MSG, argCaptor.getValue());
    }