* @param parameter add a new parameter
     * @throws DuplicateParameterException if any
     */
    public void addParameter(Parameter parameter) throws DuplicateParameterException {
        if (parameters.contains(parameter)) {
            throw new DuplicateParameterException(parameter.getName()
                    + " has been declared multiple times in mojo with goal: " + getGoal() + " (implementation: "