spanStarted(span) {
		this.spans[span.id] = {
			span,
			children: []
		};

		if (span.parentID) {
			const parentItem = this.spans[span.parentID];
			if (parentItem) parentItem.children.push(span.id);
		}
	}
Span is started.

@param {Span} span
@memberof ConsoleTraceExporter