code: public void closeMbox(final OtpMbox mbox, final OtpErlangObject reason) {
          if (mbox != null) {
              mboxes.remove(mbox);
              mbox.name = null;
              mbox.breakLinks(reason);
          }
      }
docs: Close the specified mailbox with the given reason.
  
  @param mbox
  the mailbox to close.
  @param reason
  an Erlang term describing the reason for the termination.
  
  <p>
  After this operation, the mailbox will no longer be able to
  receive messages. Any delivered but as yet unretrieved
  messages can still be retrieved however.
  </p>
  
  <p>
  If there are links from the mailbox to other
  {@link OtpErlangPid pids}, they will be broken when this
  method is called and exit signals with the given reason will
  be sent.
  </p>