`to_json()` generates updates about ypy

[ellisonbg]

Hmm, that is a good mystery...

[davidbrochart]

@dmonad any idea?

[davidbrochart]

@Horusiath @Waidhoferj ?

[chwzr]

Calling Y.encode_state_vector() is also producing empty updates:

import y_py as Y

ydoc = Y.YDoc()

def cb(event):
    print("update:", event.get_update())

ydoc.observe_after_transaction(cb)

state = Y.encode_state_vector(ydoc)

will print:

update: b'\x00\x00'