def load_self_descendants
      file = ClassFinder.where_is(self)
      path = File.expand_path(File.dirname(file))
      Dir["#{path}/**/*.rb"].each { |f| load f }
    end
def load_self_descendants
      file = ClassFinder.where_is(self)
      path = File.expand_path(File.dirname(file))
      Dir["#{path}/**/*.rb"].each { |f| load f }
    end
Find and load all ruby files under the same directory structure
 of the declared class which is including DescendantsLoader module.

 This is the trick to put the classes into ObjectSpace and have the
 desired behavior of Object.descendants and Object.subclasses.