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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_users(cls, module):
 """ Adds the `user` field to the organization user model and the link to the specific organization model. """

        try:
            cls.module_registry[module]["OrgUserModel"]._meta.get_field("user")
        except FieldDoesNotExist:
            cls.module_registry[module]["OrgUserModel"].add_to_class(
                "user",
                models.ForeignKey(
                    USER_MODEL,
                    related_name="%(app_label)s_%(class)s",
                    on_delete=models.CASCADE,
                ),
            )
        try:
            cls.module_registry[module]["OrgUserModel"]._meta.get_field("organization")
        except FieldDoesNotExist:
            cls.module_registry[module]["OrgUserModel"].add_to_class(
                "organization",
                models.ForeignKey(
                    cls.module_registry[module]["OrgModel"],
                    related_name="organization_users",
                    on_delete=models.CASCADE,
                ),
            )