Select::extractValueMultiple

static function extractValueMultiple(FieldType $fieldType, array $field, array $request)
{
	$name = $field['Field'];
	$value = isset($request[$name]) ? $request[$name] : array();

	if (!is_array($value) || is_array($value) && CBPHelper::isAssociativeArray($value))
		$value = array($value);
	$value = array_unique($value);
	$request[$name] = $value;
	return parent::extractValueMultiple($fieldType, $field, $request);
}