def init_default(data, file: false, **options)
      @type = :datablock
      @data = Datablock.new(data, file)
      @options = Hamster.hash(options)
    end
def init_default(data, file: false, **options)
      @type = :datablock
      @data = Datablock.new(data, file)
      @options = Hamster.hash(options)
    end
Initialize Dataset from given data with #to_gnuplot_points method