treeCallback method
This is called from DynamicTree.query when we are gathering pairs.
Implementation
@override
bool treeCallback(int proxyId) {
// A proxy cannot form a pair with itself.
if (proxyId == _queryProxyId) {
return true;
}
_pairBuffer.add(
Pair(
min(proxyId, _queryProxyId),
max(proxyId, _queryProxyId),
),
);
return true;
}