code: public static function delete($id = null, $connection)
      {
          if (gettype($id)!="string" && !is_numeric($id)) {
              throw new ClusterpointException("\"->delete()\" function: \"_id\" is not in valid format.", 9002);
          }
          $connection->method = 'DELETE';
          $connection->action = '['.urlencode($id).']';
          return self::sendQuery($connection);
      }
docs: Set query parametrs to execute - delete by "_id".
  
  @param  string  $id
  @param  \stdClass $connection
  @return \Clusterpoint\Response\Single