src/vs/workbench/contrib/notebook/browser/view/cellParts/codeCell.ts/CodeCell/registerMouseListener
class CodeCell:	private registerMouseListener() {
		this._register(this.templateData.editor.onMouseDown(e => {
			// prevent default on right mouse click, otherwise it will trigger unexpected focus changes
			// the catch is, it means we don't allow customization of right button mouse down handlers other than the built in ones.
			if (e.event.rightButton) {
				e.event.preventDefault();
			}
		}));
	}