StringBuilder buf = new StringBuilder();
        Supplier<Object> supplier = () -> "test \"quotes\" and \n newline";

        monitorTarget.append(buf, "specialKey", supplier);
        assertEquals("\"specialKey\":\"test \\\"quotes\\\" and \\n newline\"", buf.toString());
    }

    // Test append method with String containing backslash
    @Test
    public void test_append_stringWithBackslash() {

errors.password_no_lowercase = La password deve contenere almeno una lettera minuscola.
errors.password_no_digit = La password deve contenere almeno una cifra.
errors.password_no_special_char = La password deve contenere almeno un carattere speciale.
errors.password_is_blacklisted = Questa password non è consentita. Scegli una password diversa.
errors.invalid_confirm_password = La conferma della password non corrisponde.

            super(f, a);
            defaultField = f;
        }

        /**
         * Overrides the field query creation to handle quoted queries specially.
         * For quoted queries on the default field, creates a phrase query instead of a term query.
         *
         * @param field the field to query
         * @param queryText the query text

        return appendFileterPath(buf, escape(s));
    }

    /**
     * Escapes special regex characters in a string to create a literal pattern.
     * Handles anchor characters (^ and $) specially to preserve their regex meaning.
     *
     * @param s the string to escape
     * @return an escaped regex pattern, or empty string for comments
     */
    protected String escape(final String s) {