constructor(transport) {
    super({ objectMode: true });

    if (!transport) {
      throw new Error('ExceptionStream requires a TransportStream instance.');
    }

    // Remark (indexzero): we set `handleExceptions` here because it's the
    // predicate checked in ExceptionHandler.prototype.__getExceptionHandlers
    this.handleExceptions = true;
    this.transport = transport;
  }
Constructor function for the ExceptionStream responsible for wrapping a
TransportStream; only allowing writes of `info` objects with
`info.exception` set to true.
@param {!TransportStream} transport - Stream to filter to exceptions