allocate({[], Allocated}, _Pid) ->
    erlang:display(Allocated),
    {{[], Allocated}, {error, no_frequency}};
allocate({[Freq|Free], Allocated}, Pid) ->
    erlang:display(Allocated),
    {{Free, [{Freq, Pid}|Allocated]}, {ok, Freq}}.
deallocate({Free, Allocated}, Freq) ->
    NewAllocated=lists:keydelete(Freq, 1, Allocated),
    {[Freq|Free], NewAllocated}.