socket_timeout cannot be set to 0 in scan?

what I did was 

> scan_handler=client.scan('my_namespace','my_set')
res= scan_handler.results(policy={'socket_timeout':0})


and I got an error from here: https://github.com/aerospike/aerospike-client-c/blob/cfdfdd1d9048b4d85dbdff4f943e827f7feaf127/src/main/aerospike/as_socket.c#L466

if I don't set socket_timeout or set a positive number, I can get the result.