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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse_instant_time(slot):
 """ Parse a slot into an InstantTime object. Sample response: { "entity": "snips/datetime", "range": { "end": 36, "start": 28 }, "rawValue": "tomorrow", "slotName": "weatherForecastStartDatetime", "value": { "grain": "Day", "kind": "InstantTime", "precision": "Exact", "value": "2017-09-15 00:00:00 +00:00" } } :param slot: a intent slot. :return: a parsed InstantTime object, or None. """

        date = IntentParser.get_dict_value(slot, ['value', 'value'])
        if not date:
            return None
        date = parse(date)
        if not date:
            return None
        grain = InstantTime.parse_grain(
            IntentParser.get_dict_value(slot,
                                        ['value', 'grain']))
        return InstantTime(date, grain)