code: public boolean validate(final ValidationMethod method, final Document doc, final String fileName, final byte[] data) {
          return validate(method, doc, fileName, data, null, null);
      }
docs: Validates some piece of XML, by firstly converting it to a string to ensure that it is valid.
  
  @param method   The validation method to use during validation.
  @param doc      The XML DOM Document to be validated.
  @param fileName The filename of the DTD/Schema data.
  @param data     The DTD/Schema data to be used to validate against.
  @return True if the XML is valid, otherwise false.