original_string: public function get_key_list() {
          $keys = array();
          foreach ($this->collection as $node) {
              $keys[] = $node->key;
          }
          return $keys;
      }
code: public function get_key_list() {
          $keys = array();
          foreach ($this->collection as $node) {
              $keys[] = $node->key;
          }
          return $keys;
      }
code_tokens: public function get_key_list ( ) { $ keys = array ( ) ; foreach ( $ this -> collection as $ node ) { $ keys [ ] = $ node -> key ; } return $ keys ; }
docstring: Return a list of all the keys of all the nodes.
  @return array the keys.
docstring_tokens: Return a list of all the keys of all the nodes .