examples/selector_rewriter_chaining.rb
d=H[:div, %w(foo bar baz).map{|klz| [:p, class: klz]}]
#=> H[:div, [H[:p, {"class"=>"foo"}], H[:p, {"class"=>"bar"}], H[:p, {"class"=>"baz"}]]]
d.select {|node|node.class? 'bar'} #=> #<Hexp::Node::Selector>
.wrap(:span) #=> #<Hexp::Node::Rewriter>
.attr('data-x', '77') #=> #<Hexp::Node::Rewriter>
.wrap(:foo, 'hello' => 'jow') #=> #<Hexp::Node::Rewriter>
.attr('faz', 'foz').to_html(:include_doctype => false)
# <div>
# <p class="foo"></p>
# <foo hello="jow" faz="foz"><span data-x="77"><p class="bar"></p></span></foo><p class="baz"></p>
# </div>