ENH: Test for multi-retrieve.

test/test_caosdb.m

@@ -61,11 +61,16 @@ function test_retrieve_single()
 end
 
 %% Test retrieval of multiple Entities
-function xfail_test_retrieve_multiple()
+function test_retrieve_multiple()
   % Retrieve two entities
+  c = Caosdb();
+  violin = c.retrieve("120"){1};
   collection = c.retrieve({"120", "121"});
+
   assertEqual(length(collection), 2);
+  assertEqual(numel(collection), 2);
 
-  assertEqual(collection(1), violin);
+  assertEqual(collection{1}.id, violin.id);
+  assertEqual(collection{1}.name, violin.name);
 
 end