Represent an empty list, using the Null Object Pattern.

When inheriting from the LinkedList class, you should implement a type specific Empty class as well. Make sure you set the class instance variable @parent to the assocated list class (this allows conj, cons and make to work polymorphically).

Methods
C
E
N
Class Public methods
cons(head, tail)

Source: show 

# File lib/rake/linked_list.rb, line 95
def self.cons(head, tail)
  @parent.cons(head, tail)
end
new()

Source: show 

# File lib/rake/linked_list.rb, line 88
def initialize
end
Instance Public methods
empty?()

Source: show 

# File lib/rake/linked_list.rb, line 91
def empty?
  true
end