Add failing test

Author: vitorenesduarte

test/prop_causal_context.erl

@@ -126,9 +126,23 @@ prop_union() ->
     ).
 
 %% @private
-ds(L) ->
-    dot_set:from_dots(L).
+cc(L) ->
+    lists:foldl(
+        fun(Dot, CC) ->
+            causal_context:add_dot(Dot, CC)
+        end,
+        causal_context:new(),
+        shuffle(L)
+    ).
 
 %% @private
-cc(L) ->
-    causal_context:from_dot_set(ds(L)).
+shuffle(L) ->
+    rand:seed(exsplus, erlang:timestamp()),
+    lists:map(
+        fun({_, E}) -> E end,
+        lists:sort(
+            lists:map(
+                fun(E) -> {rand:uniform(), E} end, L
+            )
+        )
+    ).