src/vs/workbench/browser/parts/views/treeView.ts/AbstractTreeView/updateMessage
class AbstractTreeView:	protected updateMessage(): void {
		if (this._message) {
			this.showMessage(this._message);
		} else if (!this.dataProvider) {
			this.showMessage(noDataProviderMessage);
		} else {
			this.hideMessage();
		}
		this.updateContentAreas();
	}