code: public String validate(InputStream in) throws IOException, SAXException {
          try (OneOffValidator validator = new OneOffValidator(asciiQuotes, detectLanguages, forceHTML, lineOffset, loadEntities, noStream, outputFormat, schemaUrl)) {
              return validator.validate(in);
          }
      }
docs: Validate the input source
  
  @param in
  a valid {@link InputStream} to a readable file
  @return validation output {@link String}
  @throws IllegalStateException
  @throws IOException
  @throws SAXException