code: private void write(String attribute, String content)
      {
          Check.notNull(attribute);
          Check.notNull(content);
  
          try
          {
              root.setAttribute(attribute, content);
          }
          catch (final DOMException exception)
          {
              throw new LionEngineException(exception, ERROR_WRITE_ATTRIBUTE + attribute + ERROR_WRITE_CONTENT + content);
          }
      }
docs: Write a data to the root.
  
  @param attribute The attribute name (must not be <code>null</code>).
  @param content The content value (must not be <code>null</code>).
  @throws LionEngineException If error when setting the attribute.