code: def decode_int(tag, bits_per_char=6):
      
      if bits_per_char == 6:
          return _decode_int64(tag)
      if bits_per_char == 4:
          return _decode_int16(tag)
      if bits_per_char == 2:
          return _decode_int4(tag)
  
      raise ValueError('`bits_per_char` must be in {6, 4, 2}')
docs: Decode string into int assuming encoding with `encode_int()`
  
      It is using 2, 4 or 6 bits per coding character (default 6).
  
      Parameters:
          tag: str           Encoded integer.
          bits_per_char: int  The number of bits per coding character.
  
      Returns:
          int: the decoded string