code: def _entry_allocated_bitmap(self, entry_number):
      
      index, offset = divmod(entry_number, 8)
      return bool(self._bitmap[index] & (1 << offset))
docs: Checks if a particular index is allocated.
  
      Args:
          entry_number (int): Index to verify
  
      Returns:
          bool: True if it is allocated, False otherwise.