protected function assertMessageExists(int $messageNumber): void
    {
        if (true === $this->messageNumberVerified) {
            return;
        }
        $this->messageNumberVerified = true;

        $msgno = \imap_msgno($this->resource->getStream(), $messageNumber);
        if (\is_numeric($msgno) && $msgno > 0) {
            $this->imapMsgNo = $msgno;

            return;
        }

        throw new MessageDoesNotExistException(\sprintf(
            'Message "%s" does not exist',
            $messageNumber
        ));
    }
protected function assertMessageExists(int $messageNumber): void
    {
        if (true === $this->messageNumberVerified) {
            return;
        }
        $this->messageNumberVerified = true;

        $msgno = \imap_msgno($this->resource->getStream(), $messageNumber);
        if (\is_numeric($msgno) && $msgno > 0) {
            $this->imapMsgNo = $msgno;

            return;
        }

        throw new MessageDoesNotExistException(\sprintf(
            'Message "%s" does not exist',
            $messageNumber
        ));
    }
protected function assertMessageExists ( int $ messageNumber ) : void { if ( true === $ this -> messageNumberVerified ) { return ; } $ this -> messageNumberVerified = true ; $ msgno = \ imap_msgno ( $ this -> resource -> getStream ( ) , $ messageNumber ) ; if ( \ is_numeric ( $ msgno ) && $ msgno > 0 ) { $ this -> imapMsgNo = $ msgno ; return ; } throw new MessageDoesNotExistException ( \ sprintf ( 'Message "%s" does not exist' , $ messageNumber ) ) ; }
Ensure message exists.

@param int $messageNumber
Ensure message exists .