let connect = |#ca_cert: [bytes, null] = null, hostname: string, stream: io::Stream<`Tcp>|
-> Result<io::Stream<`Tls>, `TLSError(string)> 'sys_tls_connect;
let accept = |#cert: bytes, #key: bytes, stream: io::Stream<`Tcp>|
-> Result<io::Stream<`Tls>, `TLSError(string)> 'sys_tls_accept