class ActiveModel::Validations::LengthValidator

def initialize(options)
  if range = (options.delete(:in) || options.delete(:within))
    raise ArgumentError, ":in and :within must be a Range" unless range.is_a?(Range)
    options[:minimum], options[:maximum] = range.min, range.max
  end
  if options[:allow_blank] == false && options[:minimum].nil? && options[:is].nil?
    options[:minimum] = 1
  end
  super
end