code: func (h *HTTPTester) Prepare(stmt string, bSz int, tx bool) error {
  	s := make([]string, bSz)
  	for i := 0; i < len(s); i++ {
  		s[i] = stmt
  	}
  
  	b, err := json.Marshal(s)
  	if err != nil {
  		return err
  	}
  	h.br = bytes.NewReader(b)
  
  	if tx {
  		h.url = h.url + "?transaction"
  	}
  
  	return nil
  }
docs: // Prepare prepares the tester for execution.