code: function Module(moduleId, ctx, combineConfig) {
      this.moduleId = moduleId;
      this.compiler = ctx;
      this.combineConfig = combineConfig || ctx.getCombineConfig(moduleId);
      this.definition = null;
      this.prepare();
  }
docs: The module constructor
  
  @constructor
  @param {string} moduleId 模块的Id.
  @param {Compiler} ctx 整个Compiler的上下文环境，提供必要的api和保存一些全局的数据.
  @param {CombineConfig=} combineConfig combine配置信息.