protected List<CharSequenceWithOffset> split(CharSequence sequence, char delimiter) {
        List<CharSequenceWithOffset> rv = new ArrayList<>();
        int offset = 0;
        for (int i = 0; i < sequence.length(); i++) {
            char c = sequence.charAt(i);
            if (c == delimiter) {
                rv.add(new CharSequenceWithOffset(sequence.subSequence(offset, i), offset));
                offset = i + 1;
            }
        }
        rv.add(new CharSequenceWithOffset(sequence.subSequence(offset, sequence.length()), offset));
        return rv;
    }
Checks if a UTF-16 code unit represents a whitespace character (U+0020, 
U+0009, U+000C, U+000D or U+000A).
@param c the code unit
@return <code>true</code> if whitespace, <code>false</code> otherwise
src/nu/validator/datatype/AbstractDatatype.java