code: func (ctx *ReqCtx) Next() error {
  	ctx.mwIndex++
  
  	// call next middleware in the stack, if any
  	if ctx.mwIndex <= len(ctx.mw) {
  		return ctx.mw[ctx.mwIndex-1](ctx)
  	}
  
  	return nil
  }
docs: // Next executes the next middleware in the middleware stack.