def get_trees(self) -> list["Tree"]:
        """
        Get the decision trees.

        :return: A list of decision trees.
        """
        from art.metrics.verification_decisions_trees import Box, Tree

        booster_dump = self._model.get_booster().get_dump(dump_format="json")
        trees = []

        for i_tree, tree_dump in enumerate(booster_dump):
            box = Box()

            if self._model.n_classes_ == 2:
                class_label = -1
            else:
                class_label = i_tree % self._model.n_classes_

            tree_json = json.loads(tree_dump)
            trees.append(
                Tree(
                    class_id=class_label,
                    leaf_nodes=self._get_leaf_nodes(tree_json, i_tree, class_label, box),
                )
            )

        return trees

        Get the decision trees.

        :return: A list of decision trees.
        
art/estimators/classification/xgboost.py