docs: def getmtime(self, path=None, client_kwargs=None, header=None):
          """
          Return the time of last access of path.
  
          Args:
              path (str): File path or URL.
              client_kwargs (dict): Client arguments.
              header (dict): Object header.
  
          Returns:
              float: The number of seconds since the epoch
                  (see the time module).
          """
          return self._getmtime_from_header(
              self.head(path, client_kwargs, header))