code: def CA(self):
          '''
          Vertices C and A, list.
  
          '''
          try:
              return self._CA
          except AttributeError:
              pass
          self._CA = [self.C, self.A]
          return self._Cf CA(self):
          '''
          Vertices C and A, list.
  
          '''
          try:
              return self._CA
          except AttributeError:
              pass
          self._CA = [self.C, self.A]
          return self._CA
docs: Vertices C and A, list.