code: func (ca *CertAuthorityV2) Signers() ([]ssh.Signer, error) {
  	out := make([]ssh.Signer, 0, len(ca.Spec.SigningKeys))
  	for _, keyBytes := range ca.Spec.SigningKeys {
  		signer, err := ssh.ParsePrivateKey(keyBytes)
  		if err != nil {
  			return nil, trace.Wrap(err)
  		}
  		out = append(out, signer)
  	}
  	return out, nil
  }
docs: // Signers returns a list of signers that could be used to sign keys