def __init__(self, name, filename=None):
        self.name = name
        super(NamedRequirements, self).__init__(filename=filename)
def find_files(pattern, root):
  """Return all the files matching pattern below root dir."""
  for path, _, files in os.walk(root):
    for filename in fnmatch.filter(files, pattern):
      yield os.path.join(path, filename)