Empty data creates a Micro QR Code in byte mode

[heuer]

>>> import segno
>>> qr = segno.make('')
>>> qr.version
'M3'
>>> qr.mode
'byte'

Shouldn't we expect version "M1" in "alphanumeric" mode?

[heuer]

Take care:

>>> import segno
>>> qr1 = segno.make('')
>>> qr2 = qr.make(0)
>>> qr1.martrix == qr2.matrix
False
>>> qr1.version == qr2.version
True
>>> qr1.error is qr2.error
True
>>> qr1.mode != qr2.mode
True

[heuer]

Byte mode seems to be correct:

[...] Alphanumeric mode encodes data from a set of 45 characters, i.e. 10 numeric digits (0 - 9) (byte values
30HEX to 39HEX), 26 alphabetic characters (A - Z) (byte values 41HEX to 5AHEX) , and 9 symbols (SP, $, %,
*, +, -, ., /, :) (byte values 20HEX, 24HEX, 25HEX, 2AHEX, 2BHEX, 2D to 2FHEX, 3AHEX respectively). [...]