presto-geospatial/src/main/java/io/prestosql/plugin/geospatial/GeoFunctions.java/GeoFunctions/stPolygon
class GeoFunctions:    @Description("Returns a Geometry type Polygon object from Well-Known Text representation (WKT)")
    @ScalarFunction("ST_Polygon")
    @SqlType(GEOMETRY_TYPE_NAME)
    public static Slice stPolygon(@SqlType(VARCHAR) Slice input)
    {
        OGCGeometry geometry = geometryFromText(input);
        validateType("ST_Polygon", geometry, EnumSet.of(POLYGON));
        return serialize(geometry);
    }