Error: subscription `sub` can only have one root field
   ╭─[0005_subscription_with_multiple_root_fields_in_fragment_spreads.graphql:1:1]
   │
 1 │ ╭─▶ subscription sub {
   ┆ ┆   
 3 │ ├─▶ }
   │ │       
   │ ╰─────── subscription with 2 root fields
   │     
   │     Help: There are 2 root fields: newMessage, disallowedSecondRootField. This is not allowed.
───╯