The fields to include.
The fields to include. The resulting objects will also contain these fields.
(addFields: StringAdd).self
(addFields: StringFormat).self
(Since version 0.20.3) No longer a case class
(Since version 0.20.3) No longer a case class
(addFields: ArrowAssoc[AddFields]).x
(Since version 2.10.0) Use leftOfArrow
instead
(addFields: Ensuring[AddFields]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
$addFields stage.
MongoDB 3.4