def polygons(self):
        coords = self._coords()
        # convert from x/y to row/column indexing
        polygons = map(lambda b: asarray(b)[:, ::-1].tolist(), coords)
        return polygons
Recursively yield this expression and all subexpressions, in
dataset/ETHPy150Open lightning-viz/lightning-python/lightning/types/images.py/ImagePoly.polygons--crossover with--dataset/ETHPy150Open django/django/django/db/models/expressions.py/BaseExpression.flatten