gistfile1.rb

class TestC
  def self.call_everyone obj
    obj.public_method
    obj.protected_method
    obj.private_method
  end

  def call_everyone obj
    obj.public_method
    obj.protected_method
    obj.private_method
  end

  def public_method
    puts "I'm public"
  end
  
  protected
  
  def protected_method
    puts "I'm protected, can you see me?"
  end
  
  private
  
  def private_method
    puts "I'm private"
  end
end  

test_obj = TestC.new
TestC.call_everyone test_obj
# TestC.new.call_everyone test_obj