# File lib/sanitize.rb, line 120
  def clean_node!(node)
    raise ArgumentError unless node.is_a?(Nokogiri::XML::Node)

    node_whitelist = Set.new

    unless @transformers[:breadth].empty?
      traverse_breadth(node) {|n| transform_node!(n, node_whitelist, :breadth) }
    end

    traverse_depth(node) {|n| transform_node!(n, node_whitelist, :depth) }
    node
  end