Mvt
class MvtPolygon(val exteriorRing: MvtLineString, val interiorRings: Array<MvtLineString>) : MvtGeometry
A polygon: one exterior ring plus zero or more interior rings (holes).
Ring winding is whatever MvtGeometryDecoder produced, which follows the MVT signed-area convention. Renderers that need a specific orientation re-orient themselves.
envelopeInternal delegates to the exterior ring: interior rings are contained within it by definition, so the union would be identical. This matches what JTS computed for a Polygon.