Helper::getFilterFieldKey

static function getFilterFieldKey(array $field)
{
	$codeKey = 'sender_segment_filter';

	$id = $field['id'];
	if (isset($field[$codeKey]) && $field[$codeKey])
	{
		return $field[$codeKey];
	}

	if (self::isFieldTypeFilter($field['type']))
	{
		return "$id";
	}

	return "=$id";
}