Multiple lines with labels

Hi, I might be missing this feature but is there a way to have labels at the end or start of the line chart that show what each line refers to? I am not talking about touch tooltip which will show their relative numbers as well, just a generic label that stays on whether we touch line or not.

The issue does not name a file, test, or entry point. Start by locating the line-chart implementation and determine how persistent labels should be configured; done means each line can display a generic label at the start or end of the chart without relying on touch tooltips.

Written by the indexing model from the issue text.