private char forward(final int len) {
        int index = pos + len;
        while (index < arr.length) {
            char c = arr[index];
            if (isWhitespace(c)) {
                index++;
            } else {
                return c;
            }
        }

        // Return a character that I know we aren't looking for.
        return '~';
    }
Returns the char that is the specified number of chars after the current
array position ignoring whitespace chars.

@param len The number of characters after the current array position.
@return The char at the specified location or '~' if the array bounds are
exceeded as we know that '~' isn't a character this is tested
for.
stroom-core-client-widget/src/main/java/stroom/editor/client/model/XmlFormatter.java