code: function VideoProvider(spec) {
          if (!this.constructor.validProvider(spec)) {
              util.warn("Provider", "无效的Provider描述对象=>" + JSON.stringify(spec));
              return;
          }
          for (var prop in spec) {
              this[prop] = spec[prop];
          }
          if (!this.host) {
              this.host = util.uniqueKey();
          }
          if (typeof this.create !== "function") {
              this.create = util.noop;
          }
      }
docs: 视频供应商