def add(attribute, message = nil, options = {})
      message = normalize_message(attribute, message, options)
      if options[:strict]
        raise ActiveModel::StrictValidationFailed, full_message(attribute, message)
      end

      self[attribute] << message
    end
def add(attribute, message = nil, options = {})
      message = normalize_message(attribute, message, options)
      if options[:strict]
        raise ActiveModel::StrictValidationFailed, full_message(attribute, message)
      end

      self[attribute] << message
    end
Adds +message+ to the hint messages on +attribute+. More than one hint can be added to the same
 +attribute+.
 If no +message+ is supplied, <tt>:invalid</tt> is assumed.

 If +message+ is a symbol, it will be translated using the appropriate scope (see +translate_hint+).
 If +message+ is a proc, it will be called, allowing for things like <tt>Time.now</tt> to be used within an hint.