code: public GitCheckoutResponse checkout(File repositoryPath, List<File> paths)
              throws JavaGitException, IOException {
          CheckUtilities.checkFileValidity(repositoryPath);
          CheckUtilities.checkNullListArgument(paths, "list of file paths");
          GitCheckoutParser parser = new GitCheckoutParser();
          List<String> command = buildCommand(null, null, paths);
          GitCheckoutResponse response = (GitCheckoutResponse) ProcessUtilities.runCommand(repositoryPath,
                  command, parser);
          return response;
      }
docs: Checks out a list of files from repository, no checkout options provided.