code: func (o *pdOracle) GetTimestamp(ctx context.Context) (uint64, error) {
  	ts, err := o.getTimestamp(ctx)
  	if err != nil {
  		return 0, errors.Trace(err)
  	}
  	o.setLastTS(ts)
  	return ts, nil
  }
docs: // GetTimestamp gets a new increasing time.