1.0.0
2022.10.30
feat: Offer basically class decorator function.

1.1.0
2022.10.30
feat: Offer inheritance solution. Sub class can rewrite super class's state net!

1.2.0
2022.10.30
feat: Offer default state parameter to the decorator. Will modify the class's __init__
      method which can auto switch the object to the default state.
bugfix: Fix when pass an unexsited state is passed as an entry is legal.

1.2.1
2022.10.30
bugfix: Fix when default state is empty string will be ignored.

1.2.2
2022.10.30
bugfix: Fix Super class's __init__ won't be called when inherit.

1.2.3
2022.10.31
adjust: Let state attribute is visitable in __init__ when default state is set.

2.0.0
2022.11.01
reconstruct: The first augument you pass, turns their entries to their exits.
feat: Add the NoneState class, only has one instance NS. The NS state could be switch to any other states. So whether use it is your decision.
feat: Add exception classes to replace inner Exception
bugfix: Support None replace the empty set() passed.
optimize: Cut some methods' creation while not necessary.
adjust: If no default state is given and not switch to a state. The default state None will be use instead of raise an error.
adjust: Add a parameter that decide whether None state is alllowed, if allowed, an special state node called 'NS'(And writen as too) will add to the net if a None is appear in your dict passed.
adjust: Support more naming style as you want.
