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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 get_prep_value(self, value):
 """Converts timezone instances to strings for db storage."""

        # pylint: disable=newstyle
        value = super(TimeZoneField, self).get_prep_value(value)

        if isinstance(value, tzinfo):
            return value.zone

        return value