/errors/product_link_error.proto

--- v15/errors/product_link_error.proto 2024-02-20 20:29:00.000000000 +0000
+++ v16/errors/product_link_error.proto 2024-02-20 20:29:02.000000000 +0000
@@ -43,5 +43,8 @@

     // The creation request is not permitted.
     CREATION_NOT_PERMITTED = 3;
+
+    // A link cannot be created because a pending link already exists.
+    INVITATION_EXISTS = 4;
   }
 }