_onLoginCompleted (metadata, authToken, onCompleted) {
    this._initialized = true
    this._authToken = authToken
    if (metadata) {
      const serverVersion = metadata.server
      if (!this._server.version) {
        this._server.version = serverVersion
      }
    }
    if (onCompleted) {
      onCompleted(metadata)
    }
  }
Reset current failure on the observable response handler to null.