monitorTarget.append(buf, "shortKey", supplier);
        assertEquals("\"shortKey\":42", buf.toString());
    }

    // Test append method with double array
    public void test_append_doubleArray() {
        StringBuilder buf = new StringBuilder();
        double[] values = { 1.5, 2.3, 3.7 };
        Supplier<Object> supplier = () -> values;

        monitorTarget.append(buf, "arrayKey", supplier);