in (Tokenizer.java:52)
The usage of addMinorTransition will cause tokenizer wrongly tokenize the given input which contains '[' and ']' in attribute value.

For example, selector=.testSimple[message*='ndc[1]'] is a no go.

it's better to use: .addTransition(CharClass.OPEN_BRACKET, State.IN_ATTRIBUTE); in (Tokenizer.java:39)
.addTransition(CharClass.CLOSE_BRACKET, State.IN_ATTRIBUTE);; in (Tokenizer.java:52)

and provides OPEN_BRACKET, CLOSE_BRACKET in CharClass.

then do proper identification in protected CharClass getClass(Character c) implementation.