code: public BoxFolder.Info transferContent(String destinationUserID) {
          URL url = MOVE_FOLDER_TO_USER_TEMPLATE.build(this.getAPI().getBaseURL(), this.getID(), "0");
          BoxJSONRequest request = new BoxJSONRequest(this.getAPI(), url, "PUT");
          JsonObject destinationUser = new JsonObject();
          destinationUser.add("id", destinationUserID);
          JsonObject ownedBy = new JsonObject();
          ownedBy.add("owned_by", destinationUser);
          request.setBody(ownedBy.toString());
          BoxJSONResponse response = (BoxJSONResponse) request.send();
          JsonObject responseJSON = JsonObject.readFrom(response.getJSON());
          BoxFolder movedFolder = new BoxFolder(this.getAPI(), responseJSON.get("id").asString());
  
          return movedFolder.new Info(responseJSON);
      }
docs: Moves all of the owned content from within one user’s folder into a new folder in another user's account.
  You can move folders across users as long as the you have administrative permissions and the 'source'
  user owns the folders. Per the documentation at the link below, this will move everything from the root
  folder, as this is currently the only mode of operation supported.
  
  See also https://box-content.readme.io/reference#move-folder-into-another-users-folder
  
  @param destinationUserID the user id of the user that you wish to transfer content to.
  @return  info for the newly created folder.