Detailed code explanation of javascript module loader

var MyModules = (function Manager() {
  var modules = {};
  function define (name, deps, impl) {
    for(var j = 0, length = ; j < length; j++){
      deps[j] = modules[deps[j]];
    }
    modules[name] = (impl, deps);
  }

  function get (name) {
    return modules[name];
  }

  return {
    define: define,
    get: get
  }
})();

('test1', [], function() {
  function hello(name) {
    (name);
  }
  
  return {
    hello: hello
  }
});

('test2', ['test1'], function(test1) {
  function age(name, age) {
    ((name));
    (age);
  }
  
  return {
    age: age
  }
});

('test2').age('mumu', '27');