... sort.Interface for []Wallet based on the URL field.
// WalletsByURL实现了基于URL字段的[]钱包的排序接口。
type WalletsByURL []Wallet
func (w WalletsByURL) Len() int { return len(w) }
func (w WalletsByURL) Swap(i, j int) { w[i], w[j] = w[j], w[i] }
func (w Wallet...