OGCPolygon p = (OGCPolygon) g;
assertTrue(p.numInteriorRing() == 1);
OGCLineString ls = p.exteriorRing();
OGCPoint p1 = ls.pointN(1);
assertTrue(ls.pointN(1).equals(OGCGeometry.fromText("POINT(10 -10)")));
OGCPoint p2 = ls.pointN(3);
assertTrue(ls.pointN(3).equals(OGCGeometry.fromText("POINT(-10 10)")));
OGCPoint p0 = ls.pointN(0);
assertTrue(ls.pointN(0).equals(OGCGeometry.fromText("POINT(-10 -10)")));
String ms = g.convertToMulti().asText();
assertTrue(ms.equals("MULTIPOLYGON (((-10 -10, 10 -10, 10 10, -10 10, -10 -10), (-5 -5, -5 5, 5 5, 5 -5, -5 -5)))"));