91     def self.generate( tree, adaptor = nil, tree_template = TREE_TEMPLATE,  argument
93       new.to_dot( tree, adaptor, tree_template, edge_template )
105     def to_dot( tree, adaptor = nil, tree_template = TREE_TEMPLATE,  argument
109       tree_template = Context.new( tree_template, :nodes => [], :edges => [] )
110       define_nodes( tree, adaptor, tree_template )
113       define_edges( tree, adaptor, tree_template, edge_template )
114       return tree_template.to_s
117     def define_nodes( tree, adaptor, tree_template, known_nodes = nil )  argument
125         tree_template[ :nodes ] << parent_node_template
134           tree_template[ :nodes ] << node_template
138         define_nodes( child, adaptor, tree_template, edge_template )
142     def define_edges( tree, adaptor, tree_template, edge_template )  argument
158         tree_template[ :edges ] << edge_template
159         define_edges( child, adaptor, tree_template, edge_template )