code: def _int_to_binary(integer, size=None):
      
      binary_list = map(int, format(integer, 'b'))
  
      if size is None:
          return binary_list
      else:
          if len(binary_list) > size:
              # Too long, take only last n
              return binary_list[len(binary_list)-size:]
          elif size > len(binary_list):
              # Too short, pad
              return [0]*(size-len(binary_list)) + binary_list
          else:
              # Just right
              return binary_list
docs: Return bit list representation of integer.
  
      If size is given, binary string is padded with 0s, or clipped to the size.