docs: def comment_import(r, unused_dot_list):
      """Comment out import for {dot_str}."""
      unused_dot_str = ".".join(unused_dot_list)
      for n in r("ImportNode"):
          if n.names()[0] == unused_dot_str:
              # The "!" is inserted so that this line doesn't show up when searching for
              # the comment pattern in code.
              n.replace("#{}# {}".format("!", str(n)))
              break