old_contents: """
  Module for solving Rubik's Cube F2L.
  """
  
  from ....cube import *
  from ....algorithm import *
  from ....util import a_star_search
  
  class F2LPairSolver(object):
      """
      F2LPairSolver() => Solver for solving an F2L pair.
      """
      def __init__(self, cube=None, pair=None):
          self.cube = cube
          self.pair = pair
  
      def feed(self, cube, pair):
          """
          Feed Cube to the solver.
          """
          self.cube = cube
          self.pair = pair
  
      def get_pair(self):
          """
          Get the F2L pair (corner, edge).
          """
          colours = (
              self.cube[self.pair[0]].colour, 
              self.cube[self.pair[1]].colour, 
              self.cube["D"].colour
              )
          result_corner = self.cube.children
          for c in colours[:2]:
              result_corner &= self.cube.has_colour(c)
          result_edge = result_corner & self.cube.select_type("edge")
          result_corner &= self.cube.has_colour(colours[2])
          return (list(result_corner)[0], list(result_edge)[0])
          
  
new_contents: """
  Module for solving Rubik's Cube F2L.
  """
  
  from ....cube import *
  from ....algorithm import *
  from ....util import a_star_search
  
  class F2LPairSolver(object):
      """
      F2LPairSolver() => Solver for solving an F2L pair.
      """
      def __init__(self, cube=None, pair=None):
          self.cube = cube
          self.pair = pair
  
      def feed(self, cube, pair):
          """
          Feed Cube to the solver.
          """
          self.cube = cube
          self.pair = pair
  
      def get_pair(self):
          """
          Get the F2L pair (corner, edge).
          """
          colours = (
              self.cube[self.pair[0]].colour, 
              self.cube[self.pair[1]].colour, 
              self.cube["D"].colour
              )
          result_corner = self.cube.children.copy()
          for c in colours[:2]:
              result_corner &= self.cube.has_colour(c)
          result_edge = result_corner & self.cube.select_type("edge")
          result_corner &= self.cube.has_colour(colours[2])
          return (list(result_corner)[0], list(result_edge)[0])
  
          
  
subject: Fix children bug