List of expansions owned by the player.

def owned_expansions(self):
        """List of expansions owned by the player."""

        owned = {}
        for el in self.expansion_locations:
            def is_near_to_expansion(t):
                return t.position.distance_to(el) < self.EXPANSION_GAP_THRESHOLD

            th = next((x for x in self.townhalls if is_near_to_expansion(x)), None)
            if th:
                owned[el] = th

        return owned