A class for displaying various tree-like structures.

Traverses elements to create list from elements.

Ends the element output, if needed.

Ends the list of after the elements are added.

Calculates the total number of root elements.

Produces a page of nested elements.

Starts the element output.

Starts the list before the elements are added.

Unsets all the children for a given top level element.

Displays array of elements hierarchically.