message: Add comment about empty string passed to createView
diff: @@ -603,6 +603,8 @@ TEST(sidre_group, string_list)
  // Put strings into the Group.
  for(auto itr = str_vec.begin(); itr != str_vec.end(); ++itr)
  {
  + // The first parameter will be ignored when creating a View in a Group
  + // that uses list collections, so we use the empty string
  View* str_view = my_strings->createViewString("", *itr);
  EXPECT_FALSE(str_view == nullptr);
  EXPECT_TRUE(str_view->isString());
  