code: protected void refresh(@NonNull T nextPath) {
          if (hasPermission(nextPath)) {
              mCurrentPath = nextPath;
              isLoading = true;
              getLoaderManager()
                      .restartLoader(0, null, AbstractFilePickerFragment.this);
          } else {
              handlePermission(nextPath);
          }
      }
docs: Refreshes the list. Call this when current path changes. This method also checks
  if permissions are granted and requests them if necessary. See hasPermission()
  and handlePermission(). By default, these methods do nothing. Override them if
  you need to request permissions at runtime.
  
  @param nextPath path to list files for