The key associated with a Message field.
A contract for a container envelope for a value, which can allow for setting extra field metadata associated with the value.
A contract for a container envelope for a request value, which can allow for setting extra field metadata associated with the value.
A contract for a container envelope for a response value, which can allow for setting extra field metadata associated with the value.
The key associated with a Message field.
The type of value associated with this message field key.