code: public function rewind()
      {
          if ($this->_index < 0) {
              $this->_row = $this->_statement->fetch();
              $this->_index = 0;
          } else {
              throw new InvalidCallException('DataReader cannot rewind. It is a forward-only reader.');
          }
      }
docs: Resets the iterator to the initial state.
  This method is required by the interface [[\Iterator]].
  @throws InvalidCallException if this method is invoked twice