GraphQL: is there a way to link tasks to their parent issues?

Subject says it all. An issue can be of type ISSUE or TASK, I can see that. When a TASK, it is part of an issue (the “parent”). Is there any field linking the task to its parent issue (or vice-versa)?

Using graphiql and introspection, I can’t see any field name which suggests to be the right one. Forgotten? Not yet implemented? Or am I missing something?