code: public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException
     {
        if (this.validate == false) { return new InputSource(new ByteArrayInputStream("<!-- -->".getBytes())); }
        InputStream inputStream = null;
        URL sipXsdFile = SipEntityResolver.class.getClassLoader().getResource(SIP_XSD_FILE);
        inputStream = sipXsdFile.openStream();
        return new InputSource(inputStream);
     }
docs: {@inheritDoc}