src/vs/workbench/contrib/terminal/browser/xterm/commandNavigationAddon.ts/CommandNavigationAddon/scrollToNextLine
class CommandNavigationAddon:	scrollToNextLine(xterm: Terminal, scrollPosition: ScrollPosition = ScrollPosition.Middle, retainSelection: boolean = false): void {
		if (!retainSelection) {
			this._selectionStart = null;
		}

		if (this._currentMarker === Boundary.Bottom) {
			xterm.scrollToBottom();
			return;
		}

		if (this._currentMarker === Boundary.Top) {
			this._currentMarker = this._registerMarkerOrThrow(xterm, this._getOffset(xterm) + 1);
		} else {
			const offset = this._getOffset(xterm);
			if (this._isDisposable) {
				this._currentMarker.dispose();
			}
			this._currentMarker = this._registerMarkerOrThrow(xterm, offset + 1);
		}
		this._isDisposable = true;
		this._scrollToMarker(this._currentMarker, scrollPosition);
	}