seminar_class_method_define_method.rb

class Wizard  
  # class << self
  #   self.class_eval do
  #     define_method :convene_council do 
  #       puts "The council is in session!"
  #     end
  #   end
  # end
  
  def self.metaclass
    class << self
      self.class
    end
  end
  metaclass.send :define_method, :convene_council do 
    puts "The council is in session!"
  end
end

Wizard.convene_council