public String describe(int indent) {
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < indent; i++)
            sb.append("  ");
        String className = getClass().getName();
        className = className.substring(className.lastIndexOf(".") + 1);
        sb.append(className);
        sb.append(" ( ");
        int num = (arguments != null) ? arguments.length : 0;
        for(int i = 0; i < num; i++) {
            sb.append('\'');
            sb.append(arguments[i]);
            sb.append('\'');
            if (i < (num-1))
                sb.append(", ");
        }
        sb.append(" )\n");
        return sb.toString();
    }