### Question:
SubFormFieldDefinition extends AbstractFieldDefinition implements HasNestedForm { @Override public void setNestedForm(String nestedForm) { this.nestedForm = nestedForm; } SubFormFieldDefinition(); @Override SubFormFieldType getFieldType(); @Override String getNestedForm(); @Override void setNestedForm(String nestedForm); @Override Container getContainer(); @Override void setContainer(Container container); @Override TypeInfo getFieldTypeInfo(); @Override boolean equals(Object o); @Override int hashCode(); static final SubFormFieldType FIELD_TYPE; }### Answer:
@Test public void testValidation() { SubFormFieldDefinition fieldDefinition = getNewFieldDefinition(); Validator validator = Validation.buildDefaultValidatorFactory().getValidator(); Set<ConstraintViolation<SubFormFieldDefinition>> violations = validator.validate(fieldDefinition); assertEquals(0, violations.size()); fieldDefinition.setNestedForm(null); assertEquals(0, violations.size()); fieldDefinition.setNestedForm(""); assertEquals(0, violations.size()); }