def get_negation(event):
        """Return negation attached to an event.

        Example: "states": [{"@type": "State", "type": "NEGATION",
                             "text": "n't"}]
        """
        states = event.get('states', [])
        if not states:
            return []
        negs = [state for state in states
                if state.get('type') == 'NEGATION']
        neg_texts = [neg['text'] for neg in negs]
        return neg_texts
Return negation attached to an event.

        Example: "states": [{"@type": "State", "type": "NEGATION",
                             "text": "n't"}]