Tooltips should offer some interaction options for the end-user.
A] Tooltips can be moused over, and
B] The text of tooltips can be selected and copied (optional).

o In both cases, the tooltip should remain active/visible as long as
the mouse pointer is over the tooltip.

o This suggests that the internal timers for showing and hiding tooltips
should be changeable. For example, stopping the hidden timer when the mouse pointer has left the UI element but is still over the tooltip.