Hello, I have a requirement where a mapping with key "key" and value as string like 12:34 should be marshalled as key: "12.34". I searched for all possible documentation but could not find it. Could you please suggest how to implement this requirement. What I tried while debugging is changing the value of "canUsePlain" in encode.go at runtime to false and it worked as expected. But there is no certain way to enforce this behavior for a selected property that I could find.