    # 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