anchor.diff:  
   
   % @private
  --spec new_request(Request :: #radius_request{}, Username :: string(), NewUsername :: string()) ->
  +-spec new_request(Request :: #radius_request{}, 
  +                  Username :: undefined | binary(), 
  +                  NewUsername :: string()) ->
       NewRequest :: #radius_request{}.
   new_request(Request, Username, Username) -> Request;
   new_request(Request, _Username, NewUsername) ->
  
positive.code:     end.
  
  % @private
  -spec validate_route({Ip :: inet:ip_address(), Port :: eradius_server:port_number(), Secret :: eradius_lib:secret()}) ->
      boolean().
  validate_route({_Ip, Port, _Secret}) when not is_integer(Port); Port =< 0; Port > 65535 -> false;
  validate_route({_Ip, _Port, Secret}) when not is_list(Secret), not is_binary(Secret) -> false;
  
negative.code: 
  % @private
  -spec get_key(Username :: binary() | string(), Type :: atom(), Strip :: boolean(), Separator :: list()) ->
      {Key :: not_found | string(), NewUsername :: string()}.
  get_key(Username, Type, Strip, Separator) when is_binary(Username) ->
      get_key(binary_to_list(Username), Type, Strip, Separator);
  get_key(Username, realm, Strip, Separator) ->
  