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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 actions(self, context=None):
 """Return a mapping of category => actions list. Actions are filtered according to :meth:`.Action.available`. if `context` is None, then current action context is used (:attr:`context`). """

        assert self.installed(), "Actions not enabled on this application"
        result = {}
        if context is None:
            context = self.context

        for cat, actions in self._state["categories"].items():
            result[cat] = [a for a in actions if a.available(context)]
        return result