context.go
func (x *Context) URLParam(key string) string {
	for k := len(x.URLParams.Keys) - 1; k >= 0; k-- {
		if x.URLParams.Keys[k] == key {
			return x.URLParams.Values[k]
		}
	}
	return ""
}
func (x *Context) URLParam(key string) string {
	for k := len(x.URLParams.Keys) - 1; k >= 0; k-- {
		if x.URLParams.Keys[k] == key {
			return x.URLParams.Values[k]
		}
	}
	return ""
}
// URLParam returns the corresponding URL parameter value from the request
// routing context.