def get_subregions(self, iso_code):
items = OrderedDict()<EOL>for key, value in self.region_registry.items():<EOL><INDENT>code_elements, is_subregion = self._code_elements(key)<EOL>if is_subregion and code_elements[<NUM_LIT:0>] == iso_code:<EOL><INDENT>items[key] = value<EOL><DEDENT><DEDENT>return items<EOL>
Returns subregion calendar classes for given region iso_code.

>>> registry = IsoRegistry()
>>> # assuming calendars registered are: DE, DE-HH, DE-BE
>>> registry.get_subregions('DE')
{'DE-HH': <class 'workalendar.europe.germany.Hamburg'>,
'DE-BE': <class 'workalendar.europe.germany.Berlin'>}
:rtype dict
:return dict where keys are ISO codes strings
and values are calendar classes