function cb(callback) {
  callback = _.isArguments(callback) ? acb(callback) : callback
  return function (err, result) {
    if (err) return fail(err, callback)
    done(result, callback)
  }
}
function cb(callback) {
  callback = _.isArguments(callback) ? acb(callback) : callback
  return function (err, result) {
    if (err) return fail(err, callback)
    done(result, callback)
  }
}
function cb ( callback ) { callback = _ . isArguments ( callback ) ? acb ( callback ) : callback return function ( err , result ) { if ( err ) return fail ( err , callback ) done ( result , callback ) } }
wrap callback
wrap callback