def file(name_with_path)
      path, name = File.split(name_with_path)
      group(path).file(name).first
    end
def file(name_with_path)
      path, name = File.split(name_with_path)
      group(path).file(name).first
    end
Return the file that matches the specified path. This will traverse
 the project's groups and find the file at the end of the path.

 @param [String] name_with_path the path to the file
 @return [FileReference] the file that matches the name, nil if no file
   matches the path.