fails:Module#public_class_method accepts more than one method at a time
fails:Module#public_class_method raises a NameError if class method doesn't exist
fails:Module#public_class_method makes a class method public
fails:Module#public_class_method raises a NameError when the given name is not a method
fails:Module#public_class_method raises a NameError when the given name is an instance method
