src/vs/workbench/browser/parts/views/treeView.ts/TreeView/create
class TreeView:	private create() {
		this.domNode = DOM.$('.tree-explorer-viewlet-tree-view');
		this.messageElement = DOM.append(this.domNode, DOM.$('.message'));
		this.treeContainer = DOM.append(this.domNode, DOM.$('.customview-tree'));
		this.treeContainer.classList.add('file-icon-themable-tree', 'show-file-icons');
		const focusTracker = this._register(DOM.trackFocus(this.domNode));
		this._register(focusTracker.onDidFocus(() => this.focused = true));
		this._register(focusTracker.onDidBlur(() => this.focused = false));
	}