fix unreachable code & missing stringer-generated code

rpc/frametype_string.go

@@ -0,0 +1,27 @@
+// Code generated by "stringer -type=FrameType"; DO NOT EDIT.
+
+package rpc
+
+import "fmt"
+
+const (
+	_FrameType_name_0 = "FrameTypeHeaderFrameTypeDataFrameTypeTrailer"
+	_FrameType_name_1 = "FrameTypeRST"
+)
+
+var (
+	_FrameType_index_0 = [...]uint8{0, 15, 28, 44}
+	_FrameType_index_1 = [...]uint8{0, 12}
+)
+
+func (i FrameType) String() string {
+	switch {
+	case 1 <= i && i <= 3:
+		i -= 1
+		return _FrameType_name_0[_FrameType_index_0[i]:_FrameType_index_0[i+1]]
+	case i == 255:
+		return _FrameType_name_1
+	default:
+		return fmt.Sprintf("FrameType(%d)", i)
+	}
+}