# File lib/sass/util.rb, line 295
    def check_range(name, range, value, unit='')
      grace = (-0.00001..0.00001)
      str = value.to_s
      value = value.value if value.is_a?(Sass::Script::Number)
      return value if range.include?(value)
      return range.first if grace.include?(value - range.first)
      return range.last if grace.include?(value - range.last)
      raise ArgumentError.new(
        "#{name} #{str} must be between #{range.first}#{unit} and #{range.last}#{unit}")
    end