close_outgoing

        # Ractor.close_outgoing

(from ruby core)
---
    ractor.close_outgoing -> true | false

---

Closes the outgoing port and returns its previous state. All further
attempts to Ractor.yield in the ractor, and #take from the ractor will
fail with Ractor::ClosedError.

    r = Ractor.new {sleep(500)}
    r.close_outgoing  #=> false
    r.close_outgoing  #=> true
    r.take
    # Ractor::ClosedError (The outgoing-port is already closed)