public void testQuickPolygonUnion() { var a = reader.Read("POLYGON((0 0, 100 0, 100 100, 0 100, 0 0))"); var b = reader.Read("POLYGON((50 50, 150 50, 150 150, 50 150, 50 50))"); var polygons = new [] { a, b }; var polygonCollection = new GeometryFactory().CreateGeometryCollection(polygons); var union = polygonCollection.Buffer(0); Console.WriteLine(union.AsText()); Assert.AreEqual("POLYGON ((0 0, 0 100, 50 100, 50 150, 150 150, 150 50, 100 50, 100 0, 0 0))", union.AsText()); }