src/vs/workbench/browser/parts/views/treeView.ts/AbstractTreeView/canSelectMany
class AbstractTreeView:	set canSelectMany(canSelectMany: boolean) {
		const oldCanSelectMany = this._canSelectMany;
		this._canSelectMany = canSelectMany;
		if (this._canSelectMany !== oldCanSelectMany) {
			this.tree?.updateOptions({ multipleSelectionSupport: this.canSelectMany });
		}
	}