# File lib/gruff/accumulator_bar.rb, line 9
  def draw
    raise(Gruff::IncorrectNumberOfDatasetsException) unless @data.length == 1

    accum_array = @data.first[DATA_VALUES_INDEX][0..-2].inject([0]) { |a, v| a << a.last + v}
    data 'Accumulator', accum_array
    set_colors
    @data.reverse!
    super
  end