src/vs/workbench/contrib/terminal/browser/xterm/markNavigationAddon.ts/MarkNavigationAddon/_findPreviousMarker
class MarkNavigationAddon:	private _findPreviousMarker(xterm: Terminal, skipEmptyCommands: boolean = false): number {
		if (this._currentMarker === Boundary.Top) {
			return 0;
		} else if (this._currentMarker === Boundary.Bottom) {
			return this._getMarkers(skipEmptyCommands).length - 1;
		}

		let i;
		for (i = this._getMarkers(skipEmptyCommands).length - 1; i >= 0; i--) {
			if (this._getMarkers(skipEmptyCommands)[i].line < this._currentMarker.line) {
				return i;
			}
		}

		return -1;
	}