# File lib/puppet/simple_graph.rb, line 166
166:     def reversal
167:         result = self.class.new
168:         vertices.each { |vertex| result.add_vertex(vertex) }
169:         edges.each do |edge|
170:             newedge = edge.class.new(edge.target, edge.source, edge.label)
171:             result.add_edge(newedge)
172:         end
173:         result
174:     end