@Override
    public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
        characters(ch, start, length);
    }
Writes the given ignorable characters to the given character stream.
The default implementation simply forwards the call to the
{@link #characters(char[], int, int)} method.
tika-core/src/main/java/org/apache/tika/sax/ToTextContentHandler.java