class Thor::Arguments

def check_requirement!
  unless @non_assigned_required.empty?
    names = @non_assigned_required.map do |o|
      o.respond_to?(:switch_name) ? o.switch_name : o.human_name
    end.join("', '")
    class_name = self.class.name.split('::').last.downcase
    fail RequiredArgumentMissingError, "No value provided for required #{class_name} '#{names}'"
  end
end