code: func ExcludeByHost(reject func(host string) bool) ExclusionFilter {
  	return selectionFunc(func(p Peer) bool {
  		endpoint := p.AliveMessage.GetAliveMsg().Membership.Endpoint
  		var internalEndpoint string
  		se := p.AliveMessage.GetSecretEnvelope()
  		if se != nil {
  			internalEndpoint = se.InternalEndpoint()
  		}
  		return reject(endpoint) || reject(internalEndpoint)
  	})
  }
docs: // ExcludeByHost creates a ExclusionFilter out of the given exclusion predicate