public String generateInvalidPayloadExceptionMessage(final byte[] hl7Bytes) {
        if (hl7Bytes == null) {
            return "HL7 payload is null";
        }

        return generateInvalidPayloadExceptionMessage(hl7Bytes, hl7Bytes.length);
    }
@Test
    public void testGenerateInvalidPayloadExceptionMessageWithNullPayload() {
        assertEquals("HL7 payload is null", hl7util.generateInvalidPayloadExceptionMessage(null));

        assertEquals("HL7 payload is null", hl7util.generateInvalidPayloadExceptionMessage(null, 1234));
    }