Revert "SERVER-29506 Require $changeNotification to be the first stage."

This reverts commit 2431e1356823d898ef8af16997d6f63b65b385a5.

1 files changed, 2 insertions, 8 deletions

diff --git a/src/mongo/db/pipeline/document_source_mock.h b/src/mongo/db/pipeline/document_source_mock.h
index 513994cd599..9236e55ad62 100644
--- a/src/mongo/db/pipeline/document_source_mock.h
+++ b/src/mongo/db/pipeline/document_source_mock.h
@@ -48,15 +48,9 @@ public:
     const char* getSourceName() const override;
     Value serialize(
         boost::optional<ExplainOptions::Verbosity> explain = boost::none) const override;
-
-    StageConstraints constraints() const override {
-        StageConstraints constraints;
-        constraints.requiredPosition = StageConstraints::PositionRequirement::kFirst;
-        constraints.requiresInputDocSource = false;
-        constraints.isAllowedInsideFacetStage = false;
-        return constraints;
+    InitialSourceType getInitialSourceType() const override {
+        return InitialSourceType::kInitialSource;
     }
-
     BSONObjSet getOutputSorts() override {
         return sorts;
     }