# File lib/hashie/dash.rb, line 68
    def self.inherited(klass)
      super
      (@subclasses ||= Set.new) << klass
      klass.instance_variable_set('@properties', self.properties.dup)
      klass.instance_variable_set('@defaults', self.defaults.dup)
      klass.instance_variable_set('@required_properties', self.required_properties.dup)
    end