# File lib/graphviz/family_tree/person.rb, line 73
      def is_maried_with( x )
        node = @graph.add_node( "#{@node.id}And#{x.node.id}" )
        node["shape"] = "point"
        @graph.add_edge( @node, node, "dir" => "none" )
        @graph.add_edge( node, x.node, "dir" => "none" )
        @tree.add_couple( self, x, node )
      end