add needed files

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

response.go

@@ -0,0 +1,34 @@
+package drpc
+
+import (
+	"io"
+
+	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/metadata"
+	"github.com/unistack-org/micro/v3/server"
+)
+
+var _ server.Response = &rpcResponse{}
+
+type rpcResponse struct {
+	rw     io.ReadWriter
+	header metadata.Metadata
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Codec {
+	return r.codec
+}
+
+func (r *rpcResponse) WriteHeader(hdr metadata.Metadata) {
+	for k, v := range hdr {
+		r.header[k] = v
+	}
+}
+
+func (r *rpcResponse) Write(b []byte) error {
+	return r.codec.Write(r.rw, &codec.Message{
+		Header: r.header,
+		Body:   b,
+	}, nil)
+}