tooltip not showing linebreak on \r\n

[Offbeatmammal]

in most of the chartjs chart types, I can use \r\n in the tooltip text to throw a line break. it appears not to be working as expected in treemap. I have also tried 
 and <br> - they just display as text.

is there a trick to it?

[Offbeatmammal]

there is a trick to it!

rather than return the tootlip label as a text string, split it into an array, each element then becomes a line.