initial

internal/error.go

@@ -0,0 +1,7 @@
+package internal
+
+// Error is a custom error.
+type Error string
+
+// Error is an implementation of error interface.
+func (e Error) Error() string { return string(e) }

internal/proto.go

@@ -0,0 +1,16 @@
+package internal
+
+import "github.com/gogo/protobuf/proto"
+
+// Custom contains methods to satisfy proto.Message
+// including custom methods to satisfy protobuf for
+// non-proto defined types.
+type Custom interface {
+	Size() int
+	Empty() bool
+	Bytes() []byte
+	Marshal() ([]byte, error)
+	MarshalTo(data []byte) (int, error)
+	Unmarshal(data []byte) error
+	proto.Message
+}