Return a dict with useful information that summarizes this action.

def _summarize_result(self, root_action, leaf_eot):
        """Return a dict with useful information that summarizes this action."""
        root_board = root_action.parent.board
        action_detail = root_action.position_pair
        score = self._relative_score(root_action, leaf_eot,
                                     root_action.parent.player,
                                     root_action.parent.opponent)
        # mana drain info
        total_leaves = 0
        mana_drain_leaves = 0
        for leaf in root_action.leaves():
            total_leaves += 1
            if leaf.is_mana_drain:
                mana_drain_leaves += 1
        summary = base.Summary(root_board, action_detail, score,
                               mana_drain_leaves, total_leaves)
        return summary