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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 update_org(cls, module):
 """ Adds the `users` field to the organization model """

        try:
            cls.module_registry[module]["OrgModel"]._meta.get_field("users")
        except FieldDoesNotExist:
            cls.module_registry[module]["OrgModel"].add_to_class(
                "users",
                models.ManyToManyField(
                    USER_MODEL,
                    through=cls.module_registry[module]["OrgUserModel"].__name__,
                    related_name="%(app_label)s_%(class)s",
                ),
            )

        cls.module_registry[module]["OrgModel"].invitation_model = cls.module_registry[
            module
        ][
            "OrgInviteModel"
        ]