code: public BoxRequestsFile.UploadFile getUploadRequest(File file, String destinationFolderId) {
              BoxRequestsFile.UploadFile request = new BoxRequestsFile.UploadFile(file,  destinationFolderId, getFileUploadUrl(), mSession);
              return request;
      }
docs: Gets a request that uploads a file from an existing file
  @param file  file to upload
  @param destinationFolderId   id of the parent folder for the new file
  @return  request to upload a file from an existing file