code: func (b *Blob) ClaimDate() (time.Time, error) {
  	var ct time.Time
  	claimDate := b.ss.ClaimDate
  	if claimDate.IsAnyZero() {
  		return ct, MissingFieldError("claimDate")
  	}
  	return claimDate.Time(), nil
  }
docs: // ClaimDate returns the "claimDate" field.
  // If there is no claimDate, the error will be a MissingFieldError.