func Credentials(credentials *tls.Config) ServerOption {
	return func(s *Server) {
		s.credentials = credentials
	}
}
Credentials for the RPC server
package rpc
import (
	"crypto/tls"
	"github.com/getamis/sirius/metrics"
	"google.golang.org/grpc"
)
type ServerOption func(*Server)
func APIs(apis ...API) ServerOption {
	return func(s *Server) {
		s.apis = apis
	}
}
func SeverOptions(opts ...grpc.ServerOption) ServerOption {
	return func(s *Server) {
		s.serverOpts = append(s.serverOpts, opts...)
	}
}