def is_ambiguous(self, dt, idx=None):
if idx is None:<EOL><INDENT>idx = self._find_last_transition(dt)<EOL><DEDENT>timestamp = _datetime_to_timestamp(dt)<EOL>tti = self._get_ttinfo(idx)<EOL>if idx is None or idx <= <NUM_LIT:0>:<EOL><INDENT>return False<EOL><DEDENT>od = self._get_ttinfo(idx - <NUM_LIT:1>).offset - tti.offset<EOL>tt = self._trans_list[idx]          <EOL>return timestamp < tt + od<EOL>
Whether or not the "wall time" of a given datetime is ambiguous in this
zone.

:param dt:
    A :py:class:`datetime.datetime`, naive or time zone aware.


:return:
    Returns ``True`` if ambiguous, ``False`` otherwise.

.. versionadded:: 2.6.0