def _ensure_localized(self, arg, ambiguous='<STR_LIT>', nonexistent='<STR_LIT>',<EOL>from_utc=False):
<EOL>tz = getattr(self, '<STR_LIT>', None)<EOL>if tz is not None:<EOL><INDENT>if not isinstance(arg, type(self)):<EOL><INDENT>arg = self._simple_new(arg)<EOL><DEDENT>if from_utc:<EOL><INDENT>arg = arg.tz_localize('<STR_LIT>').tz_convert(self.tz)<EOL><DEDENT>else:<EOL><INDENT>arg = arg.tz_localize(<EOL>self.tz, ambiguous=ambiguous, nonexistent=nonexistent<EOL>)<EOL><DEDENT><DEDENT>return arg<EOL>
Ensure that we are re-localized.

This is for compat as we can then call this on all datetimelike
arrays generally (ignored for Period/Timedelta)

Parameters
----------
arg : Union[DatetimeLikeArray, DatetimeIndexOpsMixin, ndarray]
ambiguous : str, bool, or bool-ndarray, default 'raise'
nonexistent : str, default 'raise'
from_utc : bool, default False
    If True, localize the i8 ndarray to UTC first before converting to
    the appropriate tz. If False, localize directly to the tz.

Returns
-------
localized array