func (c *Canceler) Cancelable() bool {
	c.lock.Lock()
	length := len(c.reqChCancel)
	c.lock.Unlock()

	return length > 0
}
func (c *Canceler) Cancelable() bool {
	c.lock.Lock()
	length := len(c.reqChCancel)
	c.lock.Unlock()

	return length > 0
}
// Cancelable indicates whether there are operations that support cancelation