@Override
        void process(GlobToRegex converter, char c) {
          if (c == '*') {
            converter.appendStarStar();
            converter.popState();
          } else {
            converter.appendStar();
            converter.popState();
            converter.currentState().process(converter, c);
          }
        }
State following the reading of a single *.
jimfs/src/main/java/com/google/common/jimfs/GlobToRegex.java