try_to_add
try_to_add("TCP-AO established: add TCP-MD5 key",
try_to_add("TCP-MD5 established: add TCP-AO key",
try_to_add("non-signed established: add TCP-AO key",
try_to_add("TCP-AO key intersects with existing TCP-MD5 key",
try_to_add("TCP-MD5 key intersects with existing TCP-AO key",