@Override
    public void setErrorHandler(ErrorHandler handler) {
        if (errorHandlerLocked) {
            return;
        }
        if (handler == null) {
            handler = base;
        }
        this.errorHandler = handler;
    }
<b>SAX1, SAX2</b>: Set the error handler for this parser.

@param handler
           The object to receive error events.
src/nu/validator/gnu/xml/aelfred2/SAXDriver.java