How to group xlines in legend

I'm trying to plot various vertical lines on my graph. They all represent aspects of the same feature and only need one entry in the legend. This is the code I wrote (that seemed to work a few days ago):

ax = axes
p = xline(ax, [1 2 3], "g-");
hg = hggroup;
set(p, "Parent", hg);
hg.DisplayName = "My Data";
set(get(get(hg,'Annotation'),'LegendInformation'),'IconDisplayStyle','on');

However, when I run this now I get an error

"Error using matlab.graphics.chart.decoration.ConstantLine/setParentImpl - Parent must be a Cartesian axes."

I've read that ConstantLine objects like xline() can't have a Group object as a parent, unike plot(). My code works if I use plot(), but I'm not sure how to effectivly implement vertical lines using that function.

Answer 1

[Star Strider]

Using plot to plot the vertical lines is straightforward —

ax = axes;
% p = xline(ax, [1 2 3], "g-");
p = plot([1;1]*[1 2 3], ([1; 1; 1]*ylim).', 'g-');
hg = hggroup;
set(p, "Parent", hg);
hg.DisplayName = "My Data";

set(get(get(hg,'Annotation'),'LegendInformation'),'IconDisplayStyle','on');

.