anchor.diff:  
   -export(
       [ cons/1
  -    , get_path_and_query/1
       , get_query/1
  +    , set_query/2
       , to_bin/1
       , of_bin/1
       ]).
  
positive.code:     , user           = User
      , host           = Host
      , port           = Port
      , path_and_query = PathAndQuery
      , query          = _Query
      }
  ) ->
      UserOrEmpty =
  
negative.code:                 , user           = UserInfoOpt
                  , host           = HostBin
                  , port           = Port
                  , path           = PathBin
                  , query          = cow_qs:parse_qs(QueryBin)
                  },
  