code: public static boolean isValid(Geometry geometry, GeometryIndex index) {
  		validate(geometry, index);
  		return validationContext.isValid();
  	}
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 and containment, 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 True or false.
  @since 1.3.0