code: public BoxRequestsFile.CreateUploadSession getCreateUploadSessionRequest(InputStream is, String fileName, long fileSize, String folderId) {
          return new BoxRequestsFile.CreateUploadSession(is, fileName, fileSize, folderId, getUploadSessionForNewFileUrl(), mSession);
      }
docs: Gets a request that creates an upload session for uploading a new file
  @param is InputStream for the file to be uplaoded
  @param fileName the file name for the file to be created/uploaded
  @param fileSize the inputStream size (or the origin file size)
  @param folderId the folder ID where this file will be uploaded
  @return request to create an upload session for uploading a new file