presto-geospatial-toolkit/src/main/java/io/prestosql/geospatial/serde/JtsGeometrySerde.java/JtsGeometrySerde/writePoint
class JtsGeometrySerde:    private static void writePoint(Point point, SliceOutput output)
    {
        output.writeByte(GeometrySerializationType.POINT.code());
        if (!point.isEmpty()) {
            writeCoordinate(point.getCoordinate(), output);
        }
        else {
            output.writeDouble(NaN);
            output.writeDouble(NaN);
        }
    }