Background about il_hcmd_utils_ops

Could anyone please help me with il_hcmd_utils_ops?
I would like to add my own functions to the wireless-testing but it is said 
"drivers/net/wireless/iwlegacy/common.h: * il_hcmd_utils_ops etc. we
accommodate different command structures", what new structure can I use instead
of il_hcmd_utils_ops???