code: public GeometryValidationState validate(Geometry geometry, GeometryIndex index) {
  		return GeometryService.validate(geometry, toDelegate(index));
  	}
docs: Validates a geometry, focusing on changes at a specific sub-level of the geometry. The sublevel is indicated by
  passing an index. The only checks are on intersection (for coordinates) and containment (for subgeometries), we
  don't check on too few coordinates as we want to support incremental creation of polygons.
  
  @param geometry The geometry to check.
  @param index index that points to a sub-geometry, edge, vertex, etc...
  @return validation state.
  @since 2.1.0