code: public static Polygon createDummyPolygon() {
          Coordinate[] c = new Coordinate[]{new Coordinate(0.0, 0.0), new Coordinate(1.0, 1.0), new Coordinate(1.0, 0.0),
                  new Coordinate(0.0, 0.0)};
          LinearRing linearRing = gf().createLinearRing(c);
          return gf().createPolygon(linearRing, null);
      }
docs: Creates a polygon that may help out as placeholder.
  
  @return a dummy {@link Polygon}.