makeGateway("bookinfo-invalid", "fake", true, false),
				makeGateway(constants.DefaultNamespaceWaypoint, "default", false, true),
				makeGateway("bookinfo-valid", "bookinfo", true, true),
				makeGateway("no-name-convention", "default", true, true),
				makeGatewayWithRevision("bookinfo-rev", "bookinfo", true, true, "rev1"),
			},
			expectedOutFile: "combined-gateway",
		},
	}
	for _, tt := range cases {

// or `less /usr/includes/sysexits.h` if you're on Linux
//
// Picking the right range is tricky--there are a lot of reserved ones (see
// https://www.tldp.org/LDP/abs/html/exitcodes.html#EXITCODESREF) and then some
// used by convention (see sysexits).
//
// The intention here is to use 64-78 in a way that matches the attempt in
// sysexits to signify some error running istioctl, and use 79-125 as custom

// the zero value is a crash.  To bridge the gap, the
// init bool says whether this is a valid gmp value.
// doinit initializes z.i if it needs it.  This is not inherent
// to FFI, just a mismatch between Go's convention of
// making zero values useful and gmp's decision not to.
func (z *Int) doinit() {
	if z.init {
		return
	}
	z.init = true
	C.mpz_init(&z.i[0])
}