    # File lib/graphviz/graphml.rb, line 176
        def graphml_graph_edge( node )
          source = node.attributes['source']
          source = {source => node.attributes['sourceport']} if node.attributes['sourceport']
          target = node.attributes['target']
          target = {target => node.attributes['targetport']} if node.attributes['targetport']

          @current_edge = @current_graph.add_edge( source, target )

          node.each_element( ) do |child|
            #begin
              send( "graphml_graph_edge_#{child.name}".to_sym, child )
            #rescue NoMethodError => e
            #  raise "ERROR node #{child.name} can be child of graphml"
            #end
          end

          @current_edge = nil
        end