def bind_event_before(self, event, callback):
        self.app.set_event_binding(event, "before", callback)
Returns the union of a sequence of geometries
dataset/ETHPy150Open richrd/suplemon/suplemon/suplemon_module.py/Module.bind_event_before--crossover with--dataset/ETHPy150Open Toblerity/Shapely/shapely/ops.py/CollectionOperator.unary_union