   end
 
   defp items(%Xema.List{items: nil}, _list), do: :ok
-  defp items(%Xema.List{items: items, additional_items: additional_items}, list)
-    when is_list(items),
-    do: items_tuple(items, additional_items, list, 0)
-  defp items(%Xema.List{items: items}, list) do
-    items_list(items, list, 0)
-  end
+  defp items(
+    %Xema.List{items: items, additional_items: additional_items},
+    list
+  ) when is_list(items), do: items_tuple(items, additional_items, list, 0)
+  defp items(%Xema.List{items: items}, list), do: items_list(items, list, 0)
 
   defp items_list(_schema, [], _at), do: :ok
   defp items_list(schema, [item|list], at) do

      {:error, %{reason: :missing_dependency, for: key, dependency: dependency}}
    end
  end
end

  defp do_property(schema, value) do
    case Xema.validate(schema, value) do
      :ok -> :ok
      {:error, reason} -> error :invalid_property, error: reason
    end
  end

  defp get_value(map, key) when is_atom(key) do
    do_get_value(map, to_string(key), key)
  end
  defp get_value(map, key) do
    do_get_value(map, key, String.to_atom(key))
  end
  defp do_get_value(map, key_string, key_atom) do
    case {Map.get(map, key_string), Map.get(map, key_atom)} do
      {nil, nil} -> nil
      {nil, value} -> value
      {value, nil} -> value
      _ ->
        error :mixed_map
    end
  end

