Finally got it to work

collect.coffee

collect = (args...,callback) ->
  ret = {}
  len = args.length
  for i in [0...len]
    for own k,v of args[i]
      ret[k] = v
  callback(ret)
	
###
In normal JS
###

###
var collect,
  __slice = [].slice,
  __hasProp = {}.hasOwnProperty;

collect = function() {
  var args, callback, i, k, len, ret, v, _i, _j, _ref;
  args = 2 <= arguments.length ? __slice.call(arguments, 0, _i = arguments.length - 1) : (_i = 0, []), callback = arguments[_i++];
  ret = {};
  len = args.length;
  for (i = _j = 0; 0 <= len ? _j < len : _j > len; i = 0 <= len ? ++_j : --_j) {
    _ref = args[i];
    for (k in _ref) {
      if (!__hasProp.call(_ref, k)) continue;
      v = _ref[k];
      ret[k] = v;
    }
  }
  return callback(ret);
};
###