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

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

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

    @Nested

            this.retainPayload = retainPayload;
        }

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

        public byte[] getRawPayload() {
            return rawPayload;
        }

        // Helper method to set credit since parent's setter is final
        public void setCreditForTest(int credit) {
            setCredit(credit);
        }

            this.retainPayload = true;
        }

        @Override
        public boolean isRetainPayload() {
            return retainPayload;
        }

        @Override
        public byte[] getRawPayload() {
            return rawPayload;
        }

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

    /**

        @DisplayName("Should get and set raw payload")
        void testRawPayload() {
            assertNull(testMessage.getRawPayload());
            byte[] payload = new byte[] { 1, 2, 3, 4, 5 };
            testMessage.setRawPayload(payload);
            assertArrayEquals(payload, testMessage.getRawPayload());
        }
    }

    @Nested
    @DisplayName("Error Data Tests")
    class ErrorDataTests {

            return true; // Default to successful verification
        }

        public void setRetainPayload(boolean retain) {
            this.retainPayload = retain;
        }

        public byte[] getRawPayload() {
            return rawPayload;
        }

        // Expose headerStart for testing
        public int getHeaderStart() {
            return headerStart;
        }
    }

    /**

        public void retainPayload() {
        }

        @Override
        public boolean isRetainPayload() {
            return false;
        }

        @Override
        public byte[] getRawPayload() {
            return null;
        }

        @Override
        public void setRawPayload(byte[] rawPayload) {
        }
    }

            @Override
            public void setRawPayload(byte[] rawPayload) {
                // Implementation for raw payload
            }

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

            @Override
            public boolean isRetainPayload() {

            @Override
            public void setRawPayload(byte[] rawPayload) {
                // Implementation for raw payload
            }

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

            @Override
            public boolean isRetainPayload() {

        @Override
        public boolean verifySignature(byte[] buffer, int i, int size) {
            // Mock implementation
            return true;
        }

        @Override
        public byte[] getRawPayload() {
            return this.rawPayload;
        }

        @Override
        public void retainPayload() {
            // Mock implementation - do nothing
        }

        @Override

    @Override
    public boolean isError() {
        return this.isError;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.util.transport.Response#getRawPayload()
     */
    @Override
    public byte[] getRawPayload() {
        return this.rawPayload;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.util.transport.Response#setRawPayload(byte[])
     */