public byte[] getRawPayload() {
                // Implementation for getting raw payload
                return null;
            }

            @Override
            public boolean isRetainPayload() {
                // Implementation for retain payload flag
                return false;
            }

            @Override
            public void retainPayload() {

        @Override
        public void setSessionId(long sessionId) {
            this.sessionId = sessionId;
        }

        // Message interface methods
        @Override
        public boolean isRetainPayload() {
            return this.retainPayload;
        }

        @Override
        public void setRawPayload(byte[] rawPayload) {
            this.rawPayload = rawPayload;
        }

        bufferIndex += readAndXWireFormat(buffer, bufferIndex);

        final int len = bufferIndex - start;
        this.length = len;

        if (isRetainPayload()) {
            final byte[] payload = new byte[len];
            System.arraycopy(buffer, 4, payload, 0, len);
            setRawPayload(payload);
        }

        if (!verifySignature(buffer, 4, len)) {

            byte[] payload = new byte[] { 1, 2, 3, 4, 5 };

            assertNull(testBlock.getRawPayload());
            assertFalse(testBlock.isRetainPayload());

            testBlock.retainPayload();
            assertTrue(testBlock.isRetainPayload());

            testBlock.setRawPayload(payload);
            assertArrayEquals(payload, testBlock.getRawPayload());
        }
    }

    @Nested

        @Test
        @DisplayName("Should retain payload when requested")
        void testRetainPayload() {
            assertFalse(testMessage.isRetainPayload());
            testMessage.retainPayload();
            assertTrue(testMessage.isRetainPayload());
        }

        @Test
        @DisplayName("Should get and set raw payload")
        void testRawPayload() {