public function render_set_fields()
{
$x = array();
if ($this->args['set']) {
foreach ($this->args['set'] as $field => $value) {
if (is_object($field)) {
$field = $this->consume($field);
} else {
$field = $this->bt($field);
}
$x[] = $field;
}
}
return implode(',', $x);
}