op = promiseReturningOperators[key];
  function fn(...args) {
    if (new.target) {
      throw ERR_ILLEGAL_CONSTRUCTOR();
    }
    return ReflectApply(op, this, args);
  }
  ObjectDefineProperty(fn, 'name', { __proto__: null, value: op.name });
  ObjectDefineProperty(fn, 'length', { __proto__: null, value: op.length });
  ObjectDefineProperty(Stream.Readable.prototype, key, {
    __proto__: null,
    value: fn,
    enumerable: false,
    configurable: true,
    writable: true,
  });
}
Stream.Writable = require('internal/streams/writable');
Stream.Duplex = require('internal/streams/duplex');
Stream.Transform = require('internal/streams/transform');
Stream.PassThrough = require('internal/streams/passthrough');
Stream.pipeline = pipeline;
const { addAbortSignal } = require('internal/streams/add-abort-signal');
Stream.addAbortSignal = addAbortSignal;
Stream.finished = eos;
Stream.destroy = destroyer;
Stream.compose = compose;
Stream.setDefaultHighWaterMark = setDefaultHighWaterMark;
Stream.getDefaultHighWaterMark = getDefaultHighWaterMark;

ObjectDefineProperty(Stream, 'promises', {
  __proto__: null,
  configurable: true,
  enumerable: true,
  get() {
    return promises;
  },
});

ObjectDefineProperty(pipeline, customPromisify, {
  __proto__: null,
  enumerable: true,
  get() {
    return promises.pipeline;
  },
});

ObjectDefineProperty(eos, customPromisify, {
  __proto__: null,
  enumerable: true,
  get() {
    return promises.finished;
  },
});

// Backwards-compat with node 0.4.x
Stream.Stream = Stream;

Stream._isUint8Array = require('internal/util/types').isUint8Array;
Stream._uint8ArrayToBuffer = function _uint8ArrayToBuffer(chunk) {
  return new internalBuffer.FastBuffer(chunk.buffer,
                                       chunk.byteOffset,
                                       chunk.byteLength);
};