code: func (cb *Chequebook) AutoDeposit(interval time.Duration, threshold, buffer *big.Int) {
  	defer cb.lock.Unlock()
  	cb.lock.Lock()
  	cb.threshold = threshold
  	cb.buffer = buffer
  	cb.autoDeposit(interval)
  }
docs: // AutoDeposit (re)sets interval time and amount which triggers sending funds to the
  // chequebook. Contract backend needs to be set if threshold is not less than buffer, then
  // deposit will be triggered on every new cheque issued.