code: private String requestShareUrl(DropboxAPI<AndroidAuthSession> dropboxApi) {
          String shareUrl = null;
          if (dropboxApi != null) {
              try {
                  shareUrl = dropboxApi.share("/" + mContext.getString(R.string.wings_dropbox__photo_folder)).url;
              } catch (DropboxException e) {
                  // Do nothing.
              }
          }
          return shareUrl;
      }
docs: Requests the share url of the linked folder.
  
  @param dropboxApi the {@link DropboxAPI}.
  @return the url; or null if not linked.