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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 _structure_recipients_data(cls, recipients):
 """Converts recipients data into a list of Recipient objects. :param list recipients: list of objects :return: list of Recipient :rtype: list """

        try:  # That's all due Django 1.7 apps loading.
            from django.contrib.auth import get_user_model
            USER_MODEL = get_user_model()
        except ImportError:
            # Django 1.4 fallback.
            from django.contrib.auth.models import User as USER_MODEL

        if not is_iterable(recipients):
            recipients = (recipients,)

        objects = []
        for r in recipients:
            user = None
            if isinstance(r, USER_MODEL):
                user = r
            address = cls.get_address(r)  # todo maybe raise an exception of not a string?

            objects.append(Recipient(cls.get_alias(), user, address))

        return objects