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