code: def rename(self, path, raise_if_exists=False):
          
          if isinstance(path, HdfsTarget):
              path = path.path
          if raise_if_exists and self.fs.exists(path):
              raise RuntimeError('Destination exists: %s' % path)
          self.fs.rename(self.path, path)
docs: Does not change self.path.
  
          Unlike ``move_dir()``, ``rename()`` might cause nested directories.
          See spotify/luigi#522