setTooltip method
Sets the tooltip associated with this target.
Implementation
@override
void setTooltip(Tooltip tooltip) {
// If this is the first time that the tooltip is being set, activate it.
// We could have activated in the [onMouseOver] method when the DCL
// resolves, however, we want to call activate/deactivate on the [Tooltip]
// handle that the component presents (as it might be a proxy).
if (_tooltip == null) _delayedActivate.start();
_tooltip = tooltip;
}