code: func CompareChainKeyAlgoPriority(chain1, chain2 []*x509.Certificate) int {
  	kap1 := KeyAlgoPriority(chain1)
  	kap2 := KeyAlgoPriority(chain2)
  	return kap1 - kap2
  }
docs: // CompareChainKeyAlgoPriority ranks chains with more current key algorithm higher.