Function promise

lib/ChainInstance.js:16–26

(hwd, next)

    });
  };
  var promise = function(hwd, next) {
    return function () {
      if (!loading) {
        load();
      }

      queue.push({ hwd: hwd, args: arguments });

      return calls;
    };
  };
  var next = function () {
    if (queue.length === 0) return;