context.go
func (ctx *Context) Next() {
	// Call the next handler only if there is one and the response hasn't been written.
	if !ctx.Written() && ctx.index < len(ctx.handlersStack.Handlers)-1 {
		ctx.index++
		ctx.handlersStack.Handlers[ctx.index](ctx)
	}
}
func (ctx *Context) Next() {
	// Call the next handler only if there is one and the response hasn't been written.
	if !ctx.Written() && ctx.index < len(ctx.handlersStack.Handlers)-1 {
		ctx.index++
		ctx.handlersStack.Handlers[ctx.index](ctx)
	}
}
// Next calls the next handler in the stack, but only if the response isn't already written.