Function hipGraphLaunch 

pub unsafe extern "C" fn hipGraphLaunch(
    graphExec: hipGraphExec_t,
    stream: hipStream_t,
) -> hipError_t

@brief Launches an executable graph in the specified stream.

@param [in] graphExec - Instance of executable graph to launch. @param [in] stream - Instance of stream in which to launch executable graph. @returns #hipSuccess, #hipErrorInvalidValue