protected function mediaExpression(&$out)
{
$s = $this->seek();
$value = null;
if ($this->literal('(') && $this->expression($feature) && ($this->literal(':') && $this->expression($value) || true) && $this->literal(')')) {
$out = [Type::T_MEDIA_EXPRESSION, $feature];
if ($value) {
$out[] = $value;
}
return true;
}
$this->seek($s);
return false;
}