[Discuss-gnuradio] TypeError while using packet_sink

[anay tuljapurkar]

Hey,
     I am trying to incorporate a packet_sink into my project and everytime i do so, i receive the following error message :

TypeError  : in method 'packet_sink', argument 1 of type 'std::vector<unsigned char, std::allocator<unsigned char >> const &' , and i am trying to draw the default_access_code mentioned in the packet_utils module which is a string of 1's and 0's . What kind of type cast does it require then ? I find myself slightly confused . 

Any help would be deeply appreciated.

Thanks,
Anay.