docs: function () { var adds = function (a, b) {
                                      return function (x, y) { return [x + a, y + b] } }
          return [
              __(123).assert (123),
              __(Promise.resolve (123)).assert (123),
              __(function () { return 123 }).assert (123),
              __(function () { throw 123 }).assertRejected (123),
              __(adds ('foo', 'bar'), 123, 456).assert (['123foo', '456bar']) ] }