testLoadWhenInitializing() {
    const mm = getModuleManager({'a': []});
    mm.setLoader(createSuccessfulNonBatchLoader(mm));

    const info = {'a': {ctor: AModule, count: 0}};
    function AModule() {
      ++info['a'].count;
      BaseModule.call(this);
    }
    goog.inherits(AModule, BaseModule);
    AModule.prototype.initialize = () => {
      mm.load('a');
    };
    mm.setLoader(createSuccessfulNonBatchLoaderWithConstructor(mm, info));
    mm.preloadModule('a');
    clock.tick(5);
    assertEquals(info['a'].count, 1);
  }
Tests that a call to load the loading module during module
initialization doesn't trigger a second load.