server.go
func (ctx *RequestCtx) Error(msg string, statusCode int) {
	ctx.Response.Reset()
	ctx.SetStatusCode(statusCode)
	ctx.SetContentTypeBytes(defaultContentType)
	ctx.SetBodyString(msg)
}
func (ctx *RequestCtx) Error(msg string, statusCode int) {
	ctx.Response.Reset()
	ctx.SetStatusCode(statusCode)
	ctx.SetContentTypeBytes(defaultContentType)
	ctx.SetBodyString(msg)
}
// Error sets response status code to the given value and sets response body
// to the given message.