docs: @Override
  	public void setValueAsString(String theValue) throws DataFormatException {
  		if (theValue == null || theValue.isEmpty()) {
  			super.setValueAsString(null);
  		} else {
  			String value = theValue.trim();
  			value = preprocessXhtmlNamespaceDeclaration(value);
  
  			super.setValueAsString(value);
  		}
  	}