public function record($file, $format, $escapeDigits, $maxRecordTime = -1, $silence = false)
{
$cmd = implode(' ', array('RECORD', 'FILE', '"' . $file . '"', '"' . $format . '"', '"' . $escapeDigits . '"', '"' . $maxRecordTime . '"'));
if ($silence !== false) {
$cmd .= ' "s=' . $silence . '"';
}
return new RecordResult($this->send($cmd));
}