OptionalbufferBuffer around tile in tile-coordinate pixels.
OptionalextentTile coordinate extent.
OptionalmaxSkip this source above this zoom level.
OptionalminSkip this source below this zoom level.
OptionaltoleranceDouglas-Peucker simplification tolerance.
Per-source tiling option overrides.
Any field left
undefinedfalls through to the tile-level default and then to the built-in default via resolveOptions.