说明： 模拟以太坊MPT树 ，即默克尔树+前缀树，以levelDB存储，MPT更适合自研的区块链产品，单纯的默克尔树并没有什么用途 (Simulates the Ethernet MPT tree, namely the Merkel tree + the prefix tree, stores with the level DB, the MPT is more suitable for the self-research block chain product, the pure Merkel tree has no use)
