src/vs/workbench/contrib/notebook/browser/view/cellParts/markdownCell.ts/StatefulMarkdownCell/applyDecorations
class StatefulMarkdownCell:	private applyDecorations() {
		// apply decorations
		this._register(this.viewCell.onCellDecorationsChanged((e) => {
			e.added.forEach(options => {
				if (options.className) {
					this.notebookEditor.deltaCellOutputContainerClassNames(this.viewCell.id, [options.className], []);
				}
			});

			e.removed.forEach(options => {
				if (options.className) {
					this.notebookEditor.deltaCellOutputContainerClassNames(this.viewCell.id, [], [options.className]);
				}
			});
		}));

		this.viewCell.getCellDecorations().forEach(options => {
			if (options.className) {
				this.notebookEditor.deltaCellOutputContainerClassNames(this.viewCell.id, [options.className], []);
			}
		});
	}