def fixed_dependencies
      fixed_attrs = fixed_attributes

      filtered_dependency_attributes.each_with_object(Set.new) do |(key, value), fixed_deps|
        fixed_deps.merge(value) if fixed_attrs.include?(key)
      end.reject(&:saved?)
    end
def fixed_dependencies
      fixed_attrs = fixed_attributes

      filtered_dependency_attributes.each_with_object(Set.new) do |(key, value), fixed_deps|
        fixed_deps.merge(value) if fixed_attrs.include?(key)
      end.reject(&:saved?)
    end
Returns fixed dependencies, which are the ones we can't move, because we wouldn't be able to save the data

 @returns [Set<InventoryRefresh::InventoryCollection>] all unique non saved fixed dependencies