class Thor::Argument

def initialize(name, options = {})
  class_name = self.class.name.split('::').last
  type = options[:type]
  fail ArgumentError, "#{class_name} name can't be nil."                         if name.nil?
  fail ArgumentError, "Type :#{type} is not valid for #{class_name.downcase}s."  if type && !valid_type?(type)
  @name        = name.to_s
  @description = options[:desc]
  @required    = options.key?(:required) ? options[:required] : true
  @type        = (type || :string).to_sym
  @default     = options[:default]
  @banner      = options[:banner] || default_banner
  @enum        = options[:enum]
  validate! # Trigger specific validations
end