#definelibusbK_Set(sub_api,fn,required)\do{\pLibK_GetProcAddress((PVOID*)&WinUSBX[sub_api].fn,sub_api,KUSB_FNID_##fn);\if(required&&(WinUSBX[sub_api].fn==NULL)){\usbi_err(ctx,"LibK_GetProcAddress() failed for LibK_%s",#fn);\gotocleanup_libusbk;\}\}while(0)