Method setFlags

app/src/main/java/com/sun/mail/imap/IMAPMessage.java:1112–1145

Set/Unset the given flags in this message.

(Flags flag, boolean set)

     * Set/Unset the given flags in this message.
     */
    @Override
    public synchronized void setFlags(Flags flag, boolean set)
			throws MessagingException {
        // Acquire MessageCacheLock, to freeze seqnum.
        synchronized(getMessageCacheLock()) {
	    try {
		IMAPProtocol p = getProtocol();
		checkExpunged(); // Insure that this message is not expunged
			if (p.hasCapability("X-UIDONLY") ||
					"imap.mail.yahoo.co.jp".equals(p.getInetAddress().getHostName()) ||
					(p.hasCapability("UIDPLUS") &&
							Boolean.parseBoolean(System.getProperty("fairemail.uid_command")))) {
				// Verizon
				// Yahoo: NO [CANNOT] STORE It's not possible to perform specified operation
				long uid = getUID();
				if (uid < 0) {
					UID u = p.fetchUID(getSequenceNumber());
					if (u != null)
						uid = u.uid;
				}
				Response[] r = p.command("UID STORE " + uid +
						" " + (set ? '+' : '-') + "FLAGS " + p.createFlagList(new Flags(flag)), null);
				p.notifyResponseHandlers(r);
				p.handleResult(r[r.length - 1]);
				return;
			}
		p.storeFlags(getSequenceNumber(), flag, set);
	    } catch (ConnectionException cex) {
		throw new FolderClosedException(folder, cex.getMessage());
	    } catch (ProtocolException pex) {
		throw new MessagingException(pex.getMessage(), pex);
	    }
	}
    }

    /**
     * Set whether or not to use the PEEK variant of FETCH when