code: func (g *MetagameServer) simpleBefore(ctx context.Context, in interface{}) (interface{}, error) {
  	logger := pitaya.GetDefaultLoggerFromCtx(ctx)
  	logger.Info("Simple Before exec")
  
  	if in != nil {
  		createPlayerArgs := in.(*CreatePlayerCheatArgs)
  
  		logger.Infof("Name: %s", createPlayerArgs.Name)
  		logger.Infof("Email: %s", createPlayerArgs.Email)
  		logger.Infof("SoftCurrency: %d", createPlayerArgs.SoftCurrency)
  		logger.Infof("HardCurrency: %d", createPlayerArgs.HardCurrency)
  	}
  	return in, nil
  }
docs: // Simple example of a before pipeline that actually asserts the type of the
  // in parameter.
  // IMPORTANT: that this kind of pipeline will be hard to exist in real code
  // as a pipeline function executes for every handler and each of them
  // most probably have different parameter types.