// produces the same output as the old custom implementation

        // Test case 1: Standard padding
        final byte[] data1 = "abc".getBytes();
        assertEquals("YWJj", Base64Util.encode(data1));

        // Test case 2: Single padding
        final byte[] data2 = "abcd".getBytes();
        assertEquals("YWJjZA==", Base64Util.encode(data2));

        // Test case 3: Double padding