[antlr-interest] MismatchedRangeException never be raised?

[gaochunguang]

MismatchedRangeException's description is:
The recognizer tried to match a range of symbols, usually characters, but
could not. It tracks the minimum and maximum element in the range.

I try to find what situation MismatchedRangeException be raised.

My grammar is :

number : Digital+;
Digital : '0'..'8';

I input 9, but parser raised NoViableAltException in mTokens() method.
MismatchedRangeException never be raised?