src/vs/workbench/contrib/timeline/browser/timelinePane.ts/TimelinePane/loadMore
class TimelinePane:	private loadMore(item: LoadMoreCommand) {
		if (item.loading) {
			return;
		}

		item.loading = true;
		this.tree.rerender(item);

		if (this.pendingRequests.size !== 0) {
			return;
		}

		this._maxItemCount = this._visibleItemCount + this.pageSize;
		this.loadTimeline(false);
	}