method RpcCore.prototype._createSubscriberimport { RpcCore } from "https://dotland.deno.dev/x/polkadot@0.2.24/rpc-core/mod.ts"; _createSubscriber(unnamed 0: { subType: string; subName: string; paramsJson: AnyJson[]; update: ProviderInterfaceCallback; }, errorHandler: (error: Error) => void): Promise<number | string>Parametersunnamed 0: { subType: string; subName: string; paramsJson: AnyJson[]; update: ProviderInterfaceCallback; }errorHandler: (error: Error) => voidReturnsPromise<number | string>