创建 visionWeb javascript 库的实例。 除了实用程序函数之外，它还囊括了所有相关模块。
返回值
Object
示例
const VisionWeb = require("visionweb");
const HttpProvider = VisionWeb.providers.HttpProvider;
const PrivateKey =
"填入私钥";
const FullNode = new HttpProvider("https://infragrid.v.network");
const SolidityNode = new HttpProvider("https://infragrid.v.network");
const EventServer = new HttpProvider("https://infragrid.v.network");
const visionWeb = new VisionWeb(FullNode, SolidityNode, EventServer, PrivateKey);