class ExceptionConverter extends RuntimeException {

    private static final long serialVersionUID = 8657630363395849399L;
    /**
     * we keep a handle to the wrapped exception
     */
    private Exception ex;
    /**
     * prefix for the exception
     */
    private String prefix;

    /**
     * Construct a RuntimeException based on another Exception
     *
     * @param ex the exception that has to be turned into a RuntimeException
     */
    public ExceptionConverter(Exception ex) {
        this.ex = ex;
        prefix = (ex instanceof RuntimeException) ? "" : "ExceptionConverter: ";
    }

    /**
     * Convert an Exception into an unchecked exception. Return the exception if it is already an unchecked exception or
     * return an ExceptionConverter wrapper otherwise
     *
     * @param ex the exception to convert
     * @return an unchecked exception
     * @since 2.1.6
     */
    public static final RuntimeException convertException(Exception ex) {<FILL_FUNCTION_BODY>}

    /**
     * and allow the user of ExceptionConverter to get a handle to it.
     *
     * @return the original exception
     */
    public Exception getException() {
        return ex;
    }

    /**
     * We print the message of the checked exception
     *
     * @return message of the original exception
     */
    public String getMessage() {
        return ex.getMessage();
    }

    /**
     * and make sure we also produce a localized version
     *
     * @return localized version of the message
     */
    public String getLocalizedMessage() {
        return ex.getLocalizedMessage();
    }

    /**
     * The toString() is changed to be prefixed with ExceptionConverter
     *
     * @return String version of the exception
     */
    public String toString() {
        return prefix + ex;
    }

    /**
     * we have to override this as well
     */
    public void printStackTrace() {
        printStackTrace(System.err);
    }

    /**
     * here we prefix, with printStream.print(), not printStream.println(), the stack trace with "ExceptionConverter:"
     *
     * @param printStream printStream
     */
    public void printStackTrace(java.io.PrintStream printStream) {
        synchronized (printStream) {
            printStream.print(prefix);
            ex.printStackTrace(printStream);
        }
    }

    /**
     * Again, we prefix the stack trace with "ExceptionConverter:"
     *
     * @param printWriter printWriter
     */
    public void printStackTrace(java.io.PrintWriter printWriter) {
        synchronized (printWriter) {
            printWriter.print(prefix);
            ex.printStackTrace(printWriter);
        }
    }

    /**
     * requests to fill in the stack trace we will have to ignore. We can't throw an exception here, because this method
     * is called by the constructor of Throwable
     *
     * @return a Throwable
     */
    public synchronized Throwable fillInStackTrace() {
        return this;
    }
}

        if (ex instanceof RuntimeException) {
            return (RuntimeException) ex;
        }
        return new ExceptionConverter(ex);
    
<methods>public void <init>() ,public void <init>(java.lang.String) ,public void <init>(java.lang.Throwable) ,public void <init>(java.lang.String, java.lang.Throwable) <variables>static final long serialVersionUID