def build_send(self, entity: BaseEntity, from_user: UserType, to_user_key: RsaKey = None) -> Union[str, Dict]:
if hasattr(entity, "<STR_LIT>") and entity.outbound_doc is not None:<EOL><INDENT>rendered = entity.outbound_doc<EOL><DEDENT>else:<EOL><INDENT>rendered = entity.to_as2()<EOL><DEDENT>return rendered<EOL>
Build POST data for sending out to remotes.

:param entity: The outbound ready entity for this protocol.
:param from_user: The user sending this payload. Must have ``private_key`` and ``id`` properties.
:param to_user_key: (Optional) Public key of user we're sending a private payload to.
:returns: dict or string depending on if private or public payload.