presto-geospatial/src/main/java/io/prestosql/plugin/geospatial/GeoFunctions.java/GeoFunctions/stConvexHull
class GeoFunctions:    @Description("Returns the minimum convex geometry that encloses all input geometries")
    @ScalarFunction("ST_ConvexHull")
    @SqlType(GEOMETRY_TYPE_NAME)
    public static Slice stConvexHull(@SqlType(GEOMETRY_TYPE_NAME) Slice input)
    {
        OGCGeometry geometry = deserialize(input);
        if (geometry.isEmpty()) {
            return input;
        }
        if (GeometryType.getForEsriGeometryType(geometry.geometryType()) == POINT) {
            return input;
        }
        return serialize(geometry.convexHull());
    }