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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 _fact_to_tuple(self, fact):
 """ Convert a ``Fact`` to its normalized tuple. This is where all type conversion for ``Fact`` attributes to strings as well as any normalization happens. Note: Because different writers may require different types, we need to do this individually. Args: fact (hamster_lib.Fact):
 Fact to be converted. Returns: FactTuple: Tuple representing the original ``Fact``. """

        # Fields that may have ``None`` value will be represented by ''
        if fact.category:
            category = fact.category.name
        else:
            category = ''

        description = fact.description or ''

        return FactTuple(
            start=fact.start.strftime(self.datetime_format),
            end=fact.end.strftime(self.datetime_format),
            activity=text_type(fact.activity.name),
            duration=fact.get_string_delta(format='%M'),
            category=text_type(category),
            description=text_type(description),
        )