code: func Check(d *certdata.Data) *errors.Errors {
  	var e = errors.New(nil)
  
  	if d.Issuer != nil && !bytes.Equal(d.Cert.RawIssuer, d.Issuer.RawSubject) {
  		e.Err("Certificate Issuer Distinguished Name field MUST match the Subject DN of the Issuing CA")
  		return e
  	}
  
  	return e
  }
docs: // Check performs a strict verification on the extension according to the standard(s)