Clean up callback interfaces.

service/datastore/toggle_string.go

Index: service/datastore/toggle_string.go
diff --git a/service/datastore/toggle_string.go b/service/datastore/toggle_string.go
new file mode 100644
index 0000000000000000000000000000000000000000..5c99ab4b73c0d559e7811e8a82be5e18bc29a58e
--- /dev/null
+++ b/service/datastore/toggle_string.go
@@ -0,0 +1,16 @@
+// Code generated by "stringer -type=Toggle"; DO NOT EDIT
+
+package datastore
+
+import "fmt"
+
+const _Toggle_name = "AutoOnOff"
+
+var _Toggle_index = [...]uint8{0, 4, 6, 9}
+
+func (i Toggle) String() string {
+	if i >= Toggle(len(_Toggle_index)-1) {
+		return fmt.Sprintf("Toggle(%d)", i)
+	}
+	return _Toggle_name[_Toggle_index[i]:_Toggle_index[i+1]]
+}