src/vs/workbench/api/common/extHostTreeViews.ts/ExtHostTreeView/setSelection
class ExtHostTreeView:	setSelection(treeItemHandles: TreeItemHandle[]): void {
		if (!equals(this._selectedHandles, treeItemHandles)) {
			this._selectedHandles = treeItemHandles;
			this._onDidChangeSelection.fire(Object.freeze({ selection: this.selectedElements }));
		}
	}