old_contents: '''
  Created on 23 Oct 2013
  
  @author: richard
  '''
  
  
  class Calculator(object):
      '''
      classdocs
      '''
  
      def __init__(self):
          '''
          Constructor
          '''
  
new_contents: '''
  Created on 23 Oct 2013
  
  @author: Richard and Michael
  '''
  
  
  class Calculator(object):
      '''
      This class represents the calculation engine for the Game of Life
      simulation
      '''
  
      def __init__(self, rule_set):
          '''
          Constructor
          '''
          pass
  
      def _find_neighbour_set(self, x, y):
          '''
          Returns a collection of a cells neighbours
          '''
          pass
  
      def _next_state(self, cells):
          '''
          Returns the next state of the cell after calculation according to the
          rule set.
          '''
          pass
  
      def calculate_generation(self, grid):
          '''
          Calculates the next generation of cells in a given grid.
          '''
          pass
  
subject: Add stub methods for calculator class. Paired by Michael and Richard