# ## # ## # ## # ## 
# A single node of data in our list
class Node:
  pass

# ## # ## # ## # ## 
# the linked list 'manager' class
class LinkedList:

  # return the sum of all the values in the linked list
  def sum(self):
    pass

  # return a [list] (regular python list) from all the values in the linked list
  def to_list(self):
    pass

  # search for a given value in the list. 
  # If it is found, return True otherwise return False
  def search(self, value):
    pass
  
  # add a node with the given value to the beginning of the list
  # this doesn't need a loop -- remember the head is the beginning 
  # of the list. unshift should return the new length of the list
  def unshift(self, value):
    pass

  # reomve the value at beginning of the list
  def shift(self):
    pass

