# File lib/diffy/split_diff.rb, line 3
    def initialize(left, right, options = {})
      @format = options[:format] || Diffy::Diff.default_format

      formats = Format.instance_methods(false).map { |x| x.to_s }
      unless formats.include?(@format.to_s)
        fail ArgumentError, "Format #{format.inspect} is not a valid format"
      end

      @diff = Diffy::Diff.new(left, right, options).to_s(@format)
      @left_diff, @right_diff = split
    end