createSession abstract method
Creates a lightweight owner for resources retained across tile renders.
This is called lazily, when the tile path first needs pixels—not while the page's initial raster is being prepared. Expensive initialization should itself be deferred by the returned session until PdfTileRasterSession.rasterizeRegion, so enabling an experimental backend cannot delay first paint.
Implementation
PdfTileRasterSession? createSession(PdfRetainedScene scene);