How to use list-stream

function gitToList (gitCmd, callback) {
 var child = spawn('bash', [ '-c', gitCmd ])
 child.stdout.pipe(split2()).pipe(commitStream()).pipe(listStream.obj(callback))
}

function branchDiff (branch1, branch2, options, callback) {
 if (!branch1 || !branch2) {
  return callback(new Error('Must supply two branch names to compare'))
 }

 const repoPath = options.repoPath || process.cwd()

 findMergeBase(repoPath, branch1, branch2, (err, commit) => {
  if (err) { return callback(err) }
  map(
   [branch1, branch2], (branch, callback) => {
    collect(repoPath, branch, commit, branch === branch2 && options.endRef).pipe(listStream.obj(callback))
   }
   , (err, branchCommits) => err ? callback(err) : diffCollected(options, branchCommits, callback)
  )
 })
}