Like all OsidLists, HierarchyList provides a means for accessing Id elements sequentially either one at a time or many at a time. Examples:

                     
                     
                     while (hl.hasNext()) {
                          Hierarchy hierarchy = hl.getNextHierarchy();
                     }
                     
                                 
                     
                

                     
                     
                     while (hl.hasNext()) {
                          Hierarchy[] hierarchies = hl.getNextHierarchies(hl.available());
                     }