function cross_access ()
{
    local host
    local function from_to ()
    {
    for host in `host_list ${1}`; do
        local key="`${SSH} ${username}@${host} "cat ~/.ssh/id_rsa.pub"`"
        access $(host_list ${2})
    done;
    }
    from_to "build" "test"
    from_to "test" "build"
}