src/vs/workbench/browser/parts/views/viewPane.ts/ViewPane/constructor
class ViewPane:	getProgressIndicator() {
		if (this.progressBar === undefined) {
			// Progress bar
			this.progressBar = this._register(new ProgressBar(this.element, defaultProgressBarStyles));
			this.progressBar.hide();
		}

		if (this.progressIndicator === undefined) {
			const that = this;
			this.progressIndicator = new ScopedProgressIndicator(assertIsDefined(this.progressBar), new class extends AbstractProgressScope {
				constructor() {
					super(that.id, that.isBodyVisible());
					this._register(that.onDidChangeBodyVisibility(isVisible => isVisible ? this.onScopeOpened(that.id) : this.onScopeClosed(that.id)));
				}
			}());
		}
		return this.progressIndicator;
	}