@staticmethod
def _get_key(obj: dict, val: str) -> list:
    '\n        get list of keys with specified value from obj dictionary\n        :param dict obj: chosen dictionary\n        :param str val: specified value\n        '
    sublist = [key for (key, value) in obj.items() if (value == val)]
    if sublist:
        return sublist
    else:
        raise ValueError(('key with value %s does not exist in %s' % (val, obj)))
get list of keys with specified value from obj dictionary
:param dict obj: chosen dictionary
:param str val: specified value
@staticmethod
def _get_key(obj: dict, val: str) -> list:
    '\n        get list of keys with specified value from obj dictionary\n        :param dict obj: chosen dictionary\n        :param str val: specified value\n        '
    sublist = [key for (key, value) in obj.items() if (value == val)]
    if sublist:
        return sublist
    else:
        raise ValueError(('key with value %s does not exist in %s' % (val, obj)))