public function serialize()
{
if (!empty($this->_status[self::HIGHESTMODSEQ])) {
$msgs = count($this->_messages) > self::COMPRESSION_LIMIT ? $this->_toSequenceString($this->_messages) : implode(',', $this->_messages);
} else {
$msgs = $this->_messages;
}
return json_encode(array('s' => $this->_status, 'm' => $msgs, 'f' => $this->_serverid, 'c' => $this->_class, 'lsd' => $this->_lastSinceDate, 'sd' => $this->_softDelete, 'hi' => $this->haveInitialSync, 'v' => self::VERSION));
}