No need to import a graphId by WITH in a CALL subquery?

[cristiscu]

The following query doesn't seem to need a WITH graphId for the CALL subquery block, why?

UNWIND example.graphIds() AS graphId
CALL {
  USE example.graph(graphId)
  MATCH (movie:Movie)
  RETURN movie.released AS released
}
RETURN min(released) AS earliest