What are ControlCode and escapeSequence used in the Progress example?

[w4po]

Hello,
I saw the progress example and I don't understand the escapeSequence and ControlCode part,
I even removed this part completely and the example still works just fine with no difference?!
Removed from line 80-92 and ", new ControlCode(escapeSequence)".

spectre.console/examples/Console/Progress/Program.cs

Lines 80 to 97 in 63b940c

	const string ESC = "\u001b";
	string escapeSequence;
	if (tasks.All(i => i.IsFinished))
	{
	escapeSequence = $"{ESC}]]9;4;0;100{ESC}\\";
	}
	else
	{
	var total = tasks.Sum(i => i.MaxValue);
	var done = tasks.Sum(i => i.Value);
	var percent = (int)(done / total * 100);
	escapeSequence = $"{ESC}]]9;4;1;{percent}{ESC}\\";
	}
	var middleContent = new Grid().AddColumns(new GridColumn(), new GridColumn().Width(20));
	middleContent.AddRow(renderable, new FigletText(tasks.Count(i => i.IsFinished == false).ToString()));
	return new Rows(header, middleContent, footer, new ControlCode(escapeSequence));

[w4po]

It appears to be some kind of Ansi code to set the console window's icon like a circle progress itself.
It doesn't affect the console output at all.

Cool stuff, If anyone has more info on this please share it with us.

Edit:
Reference: Implement ConEmu's OSC 9;4 to set the taskbar progress indicator