Render the field.
$values: The values retrieved from the database.
Overrides FieldPluginBase::render
function render($values) {
$value = $values->{$this->field_alias};
if (!empty($this->options['machine_name']) || !isset($this->value_options[$value])) {
$result = check_plain($value);
}
else {
$result = $this->value_options[$value];
}
return $result;
}