CC2642R-Q1: About the argument of GATT_InitClient()

Hello

Please tell me about the argument of GATT_InitClient ().

We are implementing GATT using CC2642 and SIMPLE LINK-CC13X2-26X2-SDK_5.20.00.52.

Document is defined with an argument of void.
Examples are used with the argument "".

Is void correct for the argument?
Or is the pointer correct with "" (NULL) ?

※document
simplelink_cc13x2_26x2_sdk_5_20_00_52/docs/ble5stack/ble_user_guide/doxygen/ble/html/gatt_8h.html

※examples
simplelink_cc13x2_26x2_sdk_5_20_00_52\examples\rtos\CC26X2R1_LAUNCHXL\ble5stack\simple_peripheral