src/vs/workbench/contrib/notebook/browser/view/cellParts/cellContextKeys.ts/CellContextKeyManager/updateForCollapseState
class CellContextKeyManager:	private updateForCollapseState() {
		if (!this.element) {
			return;
		}

		this.cellContentCollapsed.set(!!this.element.isInputCollapsed);
		this.cellOutputCollapsed.set(!!this.element.isOutputCollapsed);
	}