docs: function () {  $assert (__.seq (123), 123)
                          $assert (__.seq ([123, 333]), 333)
                          $assert (__.seq ( 123, 333 ), 333)
                          $assert (__.seq ([123, _.constant (333)]), 333)
  
                          $assert (__.seq ([_.constant (333)]), 333)
  
                          return [
                              __.seq ([Promise.resolve (123), Promise.resolve (333)]).assert (333),
                              __.seq ([123, __.constant (333)]).assert (333),
                              __.seq ([123, __.rejects ('foo')]).assertRejected ('foo'),
                              __.seq ([123, __.delays (0), _.appends ('bar')]).assert ('123bar')
                          ] }