Error when running python test script

[OZ1SEJ]

The readme says: "Do the following test:

#!/usr/bin/env python3
import ais_decoder

str = "!AIVDM,1,1,,A,13HOI:0P0000VOHLCnHQKwvL05Ip,0*23\n"
ais_decoder.pushAisSentence(str, len(str))

n = ais_decoder.numAisMessages()
msg = ais_decoder.popAisMessage().asdict()

Running this test gives me

Traceback (most recent call last):
  File "./ais-test.py", line 5, in <module>
    ais_decoder.pushAisSentence(str, len(str))
AttributeError: module 'ais_decoder' has no attribute 'pushAisSentence'

on Ubuntu 20.04.