protected function copyFieldsFromInterface(InterfaceDefinition $intDef, FieldsAwareDefinitionInterface $fieldsAwareDefinition)
    {
        foreach ($intDef->getFields() as $field) {
            if (!$fieldsAwareDefinition->hasField($field->getName())) {
                $newField = clone $field;
                $newField->addInheritedFrom($intDef->getName());
                $fieldsAwareDefinition->addField($newField);
            } else {
                $fieldsAwareDefinition->getField($field->getName())->addInheritedFrom($intDef->getName());
            }
        }
    }