def make_nodes(nodes, parent_node)
      nodes.each do |name, value|
        if value.kind_of?(Hash)
          node = Ox::Element.new(name.to_s)
          make_nodes(value, node)
        else
          node = make_node(name.to_s, value)
        end
        parent_node << node
        parent_node
      end
    end
def make_nodes(nodes, parent_node)
      nodes.each do |name, value|
        if value.kind_of?(Hash)
          node = Ox::Element.new(name.to_s)
          make_nodes(value, node)
        else
          node = make_node(name.to_s, value)
        end
        parent_node << node
        parent_node
      end
    end
Make multiple nodes, appending to the parent passed to the method