code: public boolean isVertex(GeometryIndex index) {
  		if (index.hasChild()) {
  			return isVertex(index.getChild());
  		}
  		return index.getType() == GeometryIndexType.TYPE_VERTEX;
  	}
docs: Does the given index point to a vertex or not? We look at the deepest level to check this.
  
  @param index
  The index to check.
  @return true or false.