Use <vaadin-grid-tree-column> to create a column with tree toggle UI controls in the body cells.
The property itemHasChildrenPath is used for determining whether an individual item has child items
or if it's a leaf node instead.
NOTE: Hierarchical data only works with a dataProvider.
Using items will not work properly with a tree grid.
NOTE: You must explicitly import vaadin-grid-tree-column in order to use it.
Use <vaadin-grid-tree-toggle> in the cell content
to make a tree UI inside a grid. You need to update the expanded,
level, and leaf properties in your renderer.
NOTE: You must explicitly import vaadin-grid-tree-toggle in order to use it.
Use <vaadin-grid-tree-toggle> in the column body
template to make a tree UI inside a grid. Make sure you have bindings
for the expanded, level, and leaf
properties.