Method adapter

packages/socket.io/lib/index.ts:450–459

(
    v?: AdapterConstructor,
  )

  public adapter(): AdapterConstructor | undefined;
  public adapter(v: AdapterConstructor): this;
  public adapter(
    v?: AdapterConstructor,
  ): AdapterConstructor | undefined | this {
    if (!arguments.length) return this._adapter;
    this._adapter = v;
    for (const nsp of this._nsps.values()) {
      nsp._initAdapter();
    }
    return this;
  }

  /**
   * Attaches socket.io to a server or port.