dispose method
void
dispose()
Implementation
void dispose() {
for (var resource in _resourceMap.values.toList(growable: false)) {
if (resource.kind == 'BitmapData') {
removeBitmapData(resource.name);
} else if (resource.kind == 'TextureAtlas') {
removeTextureAtlas(resource.name);
} else {
_removeResource(resource.kind, resource.name);
}
}
}