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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 _iterator(self, plugins, context):
 """Yield next plug-in and instance to process. Arguments: plugins (list):
 Plug-ins to process context (pyblish.api.Context):
 Context to process """


        test = pyblish.logic.registered_test()

        for plug, instance in pyblish.logic.Iterator(plugins, context):
            if not plug.active:
                continue

            if instance is not None and instance.data.get("publish") is False:
                continue

            self.processing["nextOrder"] = plug.order

            if not self.is_running:
                raise StopIteration("Stopped")

            if test(**self.processing):
                raise StopIteration("Stopped due to %s" % test(
                    **self.processing))

            yield plug, instance