original_string: public function retrieve_group_ids(string $id_option = null, string $id_group): ?array
    {
      return $this->_retrieve_ids($id_option, null, $id_group);
    }
code: public function retrieve_group_ids(string $id_option = null, string $id_group): ?array
    {
      return $this->_retrieve_ids($id_option, null, $id_group);
    }
code_tokens: public function retrieve_group_ids ( string $ id_option = null , string $ id_group ) : ? array { return $ this -> _retrieve_ids ( $ id_option , null , $ id_group ) ; }
docstring: Returns preferences' IDs from the option's ID and the given group ID
  
  @param null|string $id_option
  @param string $id_group
  @return array|null
docstring_tokens: Returns preferences IDs from the option s ID and the given group ID