public static function getFormats() : array
    {
        return [
            self::FORMAT_GSM => self::FORMAT_GSM,
            self::FORMAT_UNICODE => self::FORMAT_UNICODE,
            self::FORMAT_BINARY => self::FORMAT_BINARY,
            self::FORMAT_WAPPUSH => self::FORMAT_WAPPUSH,
            self::FORMAT_MMS => self::FORMAT_MMS
        ];
    }
public static function getFormats() : array
    {
        return [
            self::FORMAT_GSM => self::FORMAT_GSM,
            self::FORMAT_UNICODE => self::FORMAT_UNICODE,
            self::FORMAT_BINARY => self::FORMAT_BINARY,
            self::FORMAT_WAPPUSH => self::FORMAT_WAPPUSH,
            self::FORMAT_MMS => self::FORMAT_MMS
        ];
    }
public static function getFormats ( ) : array { return [ self :: FORMAT_GSM => self :: FORMAT_GSM , self :: FORMAT_UNICODE => self :: FORMAT_UNICODE , self :: FORMAT_BINARY => self :: FORMAT_BINARY , self :: FORMAT_WAPPUSH => self :: FORMAT_WAPPUSH , self :: FORMAT_MMS => self :: FORMAT_MMS ] ; }
Returns the possible formats for the payload

@return array
Returns the possible formats for the payload