code: func checkNumParams(numParams int, info *methodInfo) error {
  	if numParams < info.numReqParams || numParams > info.maxParams {
  		if info.numReqParams == info.maxParams {
  			str := fmt.Sprintf("wrong number of params (expected "+
  				"%d, received %d)", info.numReqParams,
  				numParams)
  			return makeError(ErrNumParams, str)
  		}
  
  		str := fmt.Sprintf("wrong number of params (expected "+
  			"between %d and %d, received %d)", info.numReqParams,
  			info.maxParams, numParams)
  		return makeError(ErrNumParams, str)
  	}
  
  	return nil
  }
docs: // checkNumParams ensures the supplied number of params is at least the minimum
  // required number for the command and less than the maximum allowed.