list_treeview library Null safety

Classes

ListTreeView
ListTreeView based on ListView. ListView is the most commonly used scrolling widget. It displays its children one after another in the scroll direction. In the cross axis, the children are required to fill the ListView. The default constructor takes takes an IndexedBuilder of children.which builds the children on demand.
NodeData
This class contains information about the nodes, such as Index and level, and whether to expand. It also contains other information
TreeNode<T>
TreeNodeItem
TreeViewController
Controls the ListTreeView.