anchor.diff:              case lists:keysearch(StreamName,1,S#state.streams) of
                   {value, {StreamName,Data}} ->
                       Expected = lists:sort([Y || {X,Y} <- Data, X>=Start, X=<End]),
  -                    Observed = lists:sort([Y || {X,Y} <- Result, X>=Start, X=<End]),
  +                    Observed = lists:sort([Y || {_,Y} <- Result]),
                       Observed =:= Expected;
                   false ->
                       Result =:= []
  
positive.code:     case lists:keysearch(StreamName,1,S#state.streams) of
          {value, {StreamName,Data}} ->
              Expected = lists:sort([Y || {X,Y} <- Data, X>=Time]),
              Observed = lists:sort([Y || {X,Y} <- Result, X>=Start, X=<End]),
              Observed =:= Expected;
          false ->
              Result =:= []
  
negative.code: 
  -include_lib("proper/include/proper.hrl").
  
  -export([initial_state/0, command/1, precondition/2, postcondition/3, next_state/3]).
  
  -define(STREAMNAMES, [<<"tempfile">>, <<"file001">>, <<"anotherfile">>,
          <<"somefile">>, <<"binfile">>, <<"cakestream">>]).
  