# File lib/rgl/traversal.rb, line 238
238:     def bfs_search_tree_from (v)
239:       require 'rgl/adjacency'
240:       bfs  = bfs_iterator(v)
241:       tree = DirectedAdjacencyGraph.new
242:       bfs.set_tree_edge_event_handler { |from, to|
243:         tree.add_edge(from, to)
244:       }
245:       bfs.set_to_end                            # does the search
246:       tree
247:     end