public function availableIncludeKeys(): array
    {
        $availableKeys = [];
        if (($transformer = $this->transformer()) !== null && ($transformer instanceof  TransformerInterface)) {
            $availableKeys = $transformer->getAvailableIncludes();
        }

        return $availableKeys;
    }
public function availableIncludeKeys(): array
    {
        $availableKeys = [];
        if (($transformer = $this->transformer()) !== null && ($transformer instanceof  TransformerInterface)) {
            $availableKeys = $transformer->getAvailableIncludes();
        }

        return $availableKeys;
    }
public function availableIncludeKeys ( ) : array { $ availableKeys = [ ] ; if ( ( $ transformer = $ this -> transformer ( ) ) !== null && ( $ transformer instanceof TransformerInterface ) ) { $ availableKeys = $ transformer -> getAvailableIncludes ( ) ; } return $ availableKeys ; }
List of array keys identifying the available includes for this resource.

@return array
List of array keys identifying the available includes for this resource .