why is spine.js Module.init implemented like this?

as defined here:

Module.init is implemented like:

Module.init = Controller.init = Model.init = (a1, a2, a3, a4, a5) ->
  new this(a1, a2, a3, a4, a5)

why is it like this? why define 5 attributes and not use attrs... so attributes are not fixed to 5....

new this(attrs...)

Maybe it's because the compiled JS is much smaller (Spine.js makes a lot of emphasis on low footprint).

Module.init = Controller.init = Model.init = (a1, a2, a3, a4, a5) ->
  new this(a1, a2, a3, a4, a5)

Compiles to:

Module.init = Controller.init = Model.init = function(a1, a2, a3, a4, a5) {
  return new this(a1, a2, a3, a4, a5);
};

While:

Module.init = Controller.init = Model.init = (args...) ->
  new this args...

Compiles to the much more convoluted:

var __slice = [].slice;

Module.init = Controller.init = Model.init = function() {
  var args;
  args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
  return (function(func, args, ctor) {
    ctor.prototype = func.prototype;
    var child = new ctor, result = func.apply(child, args), t = typeof result;
    return t == "object" || t == "function" ? result || child : child;
  })(this, args, function(){});
};

This is because in JavaScript the new operator and apply cannot be used in conjunction :(