/**
   * Loads components/directives modules for given extension point. Once all the component modules are loaded, their
   * plugin definitions are returned mapped by concrete property from their definition.
   *
   * @param extensionPoint
   * @param mapBy The key to be used for their mapping in the result map. This key should be an existing property from
   *          plugin definitions for that extension point.
   * @returns {Promise.<T>|Promise} A map that contains plugin definitions for loaded modules mapped by provided key.
   */
  loadComponentModules(extensionPoint, mapBy, filterFunc) {
    var promises = [];
    let definitions = this.getPluginDefinitions(extensionPoint, mapBy);
    if (_.isFunction(filterFunc)) {
      console.log('definitions: ' + definitions);
      definitions = filterBy(definitions, filterFunc);
    }
    Object.keys(definitions).forEach((definition) => {
      promises.push(this.executeImport(definitions[definition].module));
    });
    return this.promiseAdapter.all(promises).then(() => {
      return definitions;
    });
  }