code: func (b *Blob) AsClaim() (c Claim, ok bool) {
  	if b.ss.Signer.Valid() && b.ss.Sig != "" && b.ss.ClaimType != "" && !b.ss.ClaimDate.IsAnyZero() {
  		return Claim{b}, true
  	}
  	return
  }
docs: // AsClaim returns a Claim if the receiver Blob has all the required fields.