code: function fileChanges(subject, options) {
      const operators = [
          {
              option: "reloadThrottle",
              fnName: "throttle"
          },
          {
              option: "reloadDelay",
              fnName: "delay"
          }
      ];
  
      const scheduler = options.getIn(["debug", "scheduler"]);
  
      /**
       * Create a stream buffered/debounced stream of events
       */
      const initial = getAggregatedDebouncedStream(subject, options, scheduler);
  
      return applyOperators(operators, initial, options, scheduler)
          .map(function(items) {
              const paths = items.map(x => x.path);
  
              if (
                  utils.willCauseReload(paths, options.get("injectFileTypes").toJS())
              ) {
                  return {
                      type: "reload",
                      files: items
                  };
              }
              return {
                  type: "inject",
                  files: items
              };
          })
  }
docs: Apply the operators that apply to the 'file:changed' event
  @param {Rx.Observable} subject
  @param options
  @return {Rx.Observable<{type: string, files: Array<any>}>}