Declare option not options

server/server.go

@@ -27,7 +27,7 @@ type options struct {
 	transport transport.Transport
 }
 
-type Options func(*options)
+type Option func(*options)
 
 var (
 	Address       string
@@ -36,6 +36,12 @@ var (
 	DefaultServer Server
 )
 
+func Transport(t transport.Transport) Option {
+	return func(o *options) {
+		o.transport = t
+	}
+}
+
 func Init() error {
 	defer log.Flush()