@Override
    public int LA(int i) {
        int c = stream.LA(i);
        if (c <= 0) {
            return c;
        }
        return Character.toLowerCase(c);
    }
Constructs a new CaseChangingCharStream wrapping the given {@link CharStream} forcing
all characters lower case.
@param stream The stream to wrap.
container-search/src/main/java/com/yahoo/search/yql/CaseInsensitiveCharStream.java