protected function _relationshipMustHaveData($path)
    {
        $path = $this->_getPathObject($path);

        if ($this->_hasProperty($path->dotted . '.data')) {
            return true;
        }

        $this->_errorCollection->addRelationshipError(
            $name = $path->key,
            $title = '_required',
            $detail = "Relationships object does not contain member 'data'",
            $status = null,
            $idx = null,
            $aboutLink = $this->_getAboutLink('http://jsonapi.org/format/#crud-creating')
        );

        return false;
    }