Lucem ted$ irb
>> module Mod
>>  def test
>>
>>    puts "test"
>>  end
>> end
=> nil
>> Mod.test
NoMethodError: private method `test' called for Mod:Module
	from (irb):6
>> module Mod
>>  def self.test
>>   puts "test"
>>  end
>> end
=> nil
>> Mod.test
test
=> nil
>>