func (t *T) Fail() {
	t.mu.Lock()
	defer t.mu.Unlock()
	t.failed = true
}
func (t *T) Fail() {
	t.mu.Lock()
	defer t.mu.Unlock()
	t.failed = true
}
func ( t * T ) Fail ( ) { t . mu . Lock ( ) defer t . mu . Unlock ( ) t . failed = true }
// Fail marks the task as having failed but continues execution.
Fail marks the task as having failed but continues execution .