code: function shimZlib () {
      let originalGzip = zlib.gzipSync;
      let originalGunzip = zlib.gunzipSync;
      zlib.gzipSync = function (data, options = {}) {
          options.finishFlush = zlib.Z_SYNC_FLUSH;
          return originalGzip.call(zlib, data, options);
      };
      zlib.gunzipSync = function (data, options = {}) {
          options.finishFlush = zlib.Z_SYNC_FLUSH;
          return originalGunzip.call(zlib, data, options);
      };
  }
docs: Temporarily adding this until GZIP issues are resolved: https://github.com/villadora/express-http-proxy/issues/177 /* istanbul ignore next