public void Dispose ()
{
int i, n;
if (_sites != null) {
_sites.Dispose ();
_sites = null;
}
if (_triangles != null) {
n = _triangles.Count;
for (i = 0; i < n; ++i) {
_triangles [i].Dispose ();
}
_triangles.Clear ();
_triangles = null;
}
if (_edges != null) {
n = _edges.Count;
for (i = 0; i < n; ++i) {
_edges [i].Dispose ();
}
_edges.Clear ();
_edges = null;
}
// _plotBounds = null;
_sitesIndexedByLocation = null;
}