# File rbtree.rb, line 120
 def traverse object=@root
		depth_first = proc { |node, count|
			yield(node, count)
			depth_first.call(node.left, count+1) unless node.left.nil?
			depth_first.call(node.right, count+1) unless node.right.nil?
		}
		depth_first.call object, 0
	end