cleanup() {
    if (this._inflate) {
      this._inflate.close();
      this._inflate = null;
    }

    if (this._deflate) {
      const callback = this._deflate[kCallback];

      this._deflate.close();
      this._deflate = null;

      if (callback) {
        callback(
          new Error(
            'The deflate stream was closed while data was being processed'
          )
        );
      }
    }
  }
Releases all resources used by the extension.

@public