RTOS/LAUNCHXL-CC1310: How to use UART_Params's *custom

Hi Edvard,

     Sorry， I didn't give clear inform. SDK version is simplelink_cc13x0_sdk_1_60_00_21. the uart Params is defined in uart.h.

typedef struct UART_Params_ {
    UART_Mode       readMode;        /*!< Mode for all read calls */
    UART_Mode       writeMode;       /*!< Mode for all write calls */
    uint32_t        readTimeout;     /*!< Timeout for read calls in blocking mode. */
    uint32_t        writeTimeout;    /*!< Timeout for write calls in blocking mode. */
    UART_Callback   readCallback;    /*!< Pointer to read callback function for callback mode. */
    UART_Callback   writeCallback;   /*!< Pointer to write callback function for callback mode. */
    UART_ReturnMode readReturnMode;  /*!< Receive return mode */
    UART_DataMode   readDataMode;    /*!< Type of data being read */
    UART_DataMode   writeDataMode;   /*!< Type of data being written */
    UART_Echo       readEcho;        /*!< Echo received data back */
    uint32_t        baudRate;        /*!< Baud rate for UART */
    UART_LEN        dataLength;      /*!< Data length for UART */
    UART_STOP       stopBits;        /*!< Stop bits for UART */
    UART_PAR        parityType;      /*!< Parity bit type for UART */
    void           *custom;          /*!< Custom argument used by driver implementation */
} UART_Params;