# File lib/nokogiri/xml/builder.rb, line 128
      def initialize options = {}, &block
        namespace = self.class.name.split('::')
        namespace[-1] = 'Document'
        @doc      = eval(namespace.join('::')).new
        @parent   = @doc
        @context  = nil
        @arity    = nil

        options.each do |k,v|
          @doc.send("#{k}=""#{k}=", v)
        end

        return unless block_given?

        @arity = block.arity
        if @arity <= 0
          @context = eval('self', block.binding)
          instance_eval(&block)
        else
          yield self
        end

        @parent = @doc
      end