code: func (c *Conn) ExpectationsWereMet() error {
  	errMsg := ""
  	for _, err := range c.Errors {
  		errMsg = fmt.Sprintf("%s%s\n", errMsg, err.Error())
  	}
  
  	for _, cmd := range c.commands {
  		if !cmd.Called {
  			errMsg = fmt.Sprintf("%sCommand %s with arguments %#v expected but never called.\n", errMsg, cmd.Name, cmd.Args)
  		}
  	}
  
  	if errMsg != "" {
  		return fmt.Errorf("%s", errMsg)
  	}
  
  	return nil
  }
docs: // ExpectationsWereMet can guarantee that all commands that was set on unit tests
  // called or call of unregistered command can be caught here too