private void addLiteral(int literal) {
        if (literal != INVALID_CODEPOINT) {
            literals.appendCodePoint(literal);
        }
    }
Creates a new pattern read for processing the given string.
@param sequence String with the pattern to process.
@param visitor Visitor to call for each encountered token of the pattern.
primefaces/src/main/java/org/primefaces/convert/PatternReader.java