Both the brand and the method are checked: the brand is the contract, and the
method check is what turns a node that claims the brand without implementing
the shape — the failure mode a structural contract has and a base class does
not — into a node that simply does not draw, rather than a TypeError inside
the render loop.
Narrows any value to a ParticleDrawable.
Both the brand and the method are checked: the brand is the contract, and the method check is what turns a node that claims the brand without implementing the shape — the failure mode a structural contract has and a base class does not — into a node that simply does not draw, rather than a
TypeErrorinside the render loop.