use type

Author: kmahar

Sources/MongoSwift/MongoCollection+FindAndModify.swift

@@ -41,12 +41,12 @@ extension MongoCollection {
      *   - update: a `Document` containing updates to apply
      *   - options: Optional `FindOneAndUpdateOptions` to use when executing the command
      *
-     * - Returns: Either the original or updated document depending on selected options, 
-     *            or `nil` if there was no match.
+     * - Returns: A `CollectionType` representing either the original or updated document,
+     *      depending on selected options, or `nil` if there was no match.
      */
     @discardableResult
     public func findOneAndUpdate(filter: Document, update: Document,
-                                 options: FindOneAndUpdateOptions? = nil) throws -> Document? {
+                                 options: FindOneAndUpdateOptions? = nil) throws -> CollectionType? {
         throw MongoError.commandError(message: "Unimplemented command")
     }
 }