docs: def delete_branch(self, branch_name, message=None, author=None):
          """
          Delete or close a branch in the local repository.
  
          :param branch_name: The name of the branch to delete or close (a string).
          :param message: The message to use when closing the branch requires a
                          commit (a string or :data:`None`, defaults to the
                          string "Closing branch NAME").
          :param author: Override :attr:`author` (refer to
                         :func:`coerce_author()` for details
                         on argument handling).
          """
          # Make sure the local repository exists.
          self.create()
          # Delete the branch in the local repository.
          logger.info("Deleting branch '%s' in %s ..", branch_name, format_path(self.local))
          self.context.execute(*self.get_delete_branch_command(
              author=(coerce_author(author) if author else self.author),
              message=(message or ("Closing branch %s" % branch_name)),
              branch_name=branch_name,
          ))