Companion

Keys will be shared between elements. Identical keys will only be serialized once, thus possibly saving space. But serialization performance might be slower and consumes more memory.

Strings and keys will be shared between elements.

No keys or strings will be shared

Strings will be shared between elements. Identical strings will only be serialized once, thus possibly saving space. But serialization performance might be slower and consumes more memory. This is ideal if you expect many repeated strings on the message.