metamask-extension/app/scripts/lib/stream-utils.js

import ObjectMultiplex from 'obj-multiplex'
import pump from 'pump'

/**
 * Sets up stream multiplexing for the given stream
 * @param {any} connectionStream - the stream to mux
 * @returns {stream.Stream} the multiplexed stream
 */
export function setupMultiplex(connectionStream) {
  const mux = new ObjectMultiplex()
  pump(connectionStream, mux, connectionStream, (err) => {
    if (err) {
      console.error(err)
    }
  })
  return mux
}