src/vs/workbench/contrib/terminal/browser/xterm/markNavigationAddon.ts/MarkNavigationAddon/_isEmptyCommand
class MarkNavigationAddon:	private _isEmptyCommand(marker: IMarker | Boundary) {
		if (marker === Boundary.Bottom) {
			return true;
		}

		if (marker === Boundary.Top) {
			return this._getMarkers(true).map(e => e.line).indexOf(0) === -1;
		}

		return this._getMarkers(true).indexOf(marker) === -1;
	}