CoffeeMachineInferer.py example is not running

[arpan-vs]

Hello,
I'm running the "next" branch,
but I get error:

Server is started and listenning
Connected with 127.0.0.1:52198
5025: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5026: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5027: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5028: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5028: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5029: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5029: [ERROR] NetworkActiveKnowledgeBase:_submit_letter: a bytes-like object is required, not 'str'
5029: [ERROR] ObservationTable:__execute_query: Input and output words do not have the same size
Traceback (most recent call last):
  File "/workspaces/pylstar/src/pylstar/KnowledgeBase.py", line 113, in _resolve_word
    return self.knowledge_tree.get_output_word(word)
  File "/workspaces/pylstar/src/pylstar/KnowledgeTree.py", line 181, in get_output_word
    raise Exception("No path found")
Exception: No path found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/workspaces/pylstar/src/pylstar/ObservationTable.py", line 866, in __execute_query
    self.knowledge_base.resolve_query(query)
  File "/workspaces/pylstar/src/pylstar/KnowledgeBase.py", line 103, in resolve_query
    query.output_word = self._resolve_word(query.input_word)
  File "/workspaces/pylstar/src/pylstar/KnowledgeBase.py", line 123, in _resolve_word
    self.knowledge_tree.add_word(input_word = word, output_word = output)
  File "/workspaces/pylstar/src/pylstar/KnowledgeTree.py", line 220, in add_word
    raise Exception("Input and output words do not have the same size")
Exception: Input and output words do not have the same size
Stoping coffeemachine
Coffee machine process is forced to stop
Traceback (most recent call last):
  File "/workspaces/pylstar/test/src/test_pylstar/coffee_machine_example/CoffeeMachineInferer.py", line 78, in <module>
    main()
  File "/workspaces/pylstar/test/src/test_pylstar/coffee_machine_example/CoffeeMachineInferer.py", line 62, in main
    coffee_state_machine = lstar.learn()
  File "/workspaces/pylstar/src/pylstar/LSTAR.py", line 274, in learn
    self.__initialize()
  File "/workspaces/pylstar/src/pylstar/LSTAR.py", line 368, in __initialize
    self.observation_table.initialize()
  File "/workspaces/pylstar/src/pylstar/ObservationTable.py", line 87, in initialize
    self.__add_word_in_S(Word([EmptyLetter()]))
  File "/workspaces/pylstar/src/pylstar/ObservationTable.py", line 803, in __add_word_in_S
    self.__add_word_in_SA(new_word)
  File "/workspaces/pylstar/src/pylstar/ObservationTable.py", line 843, in __add_word_in_SA
    raise Exception("Query '{}' could not be queries".format(output_query))
Exception: Query 'OutputQuery(I = [Letter('REFILL_WATER'), Letter('REFILL_WATER')], O = None)' could not be queries
Connected with 127.0.0.1:52202
Connected with 127.0.0.1:52210
Connected with 127.0.0.1:52224
Connected with 127.0.0.1:52228
Connected with 127.0.0.1:52236

How to resolve the above error @gbossert ?