# File lib/markaby/builder.rb, line 145
    def capture(&block)
      @streams.push(@builder.target = Stream.new)
      @builder.level += 1
      str = instance_eval(&block)
      str = @streams.last.join if @streams.last.any?
      @streams.pop
      @builder.level -= 1
      @builder.target = @streams.last
      str
    end