fix unreachable code & missing stringer-generated code

rpc/status_string.go

@@ -0,0 +1,17 @@
+// Code generated by "stringer -type=Status"; DO NOT EDIT.
+
+package rpc
+
+import "fmt"
+
+const _Status_name = "StatusOKStatusRequestErrorStatusServerErrorStatusError"
+
+var _Status_index = [...]uint8{0, 8, 26, 43, 54}
+
+func (i Status) String() string {
+	i -= 1
+	if i >= Status(len(_Status_index)-1) {
+		return fmt.Sprintf("Status(%d)", i+1)
+	}
+	return _Status_name[_Status_index[i]:_Status_index[i+1]]
+}