union method
Computes the union of all the elements of this geometry.
This method supports {@link GeometryCollection}s (which the other overlay operations currently do not).
The result obeys the following contract:
- Unioning a set of {@link LineString}s has the effect of fully noding and dissolving the linework.
- Unioning a set of {@link Polygon}s always returns a {@link Polygonal} geometry (unlike {@link #union(Geometry)}, which may return geometries of lower dimension if a topology collapse occurred).
@return the union geometry @throws TopologyException if a robustness error occurs
@see UnaryUnionOp
Implementation
Geometry union() {
throw UnimplementedError("Not implemented yet"); // TODO
// return UnaryUnionOp.union(this);
}