// Then
        assertEquals(expectedLength, actualLength);
        verify(messageBlock).encode(dst, dstIndex);
    }

    @Test
    @DisplayName("Test setDigest and getDigest methods")
    void testSetAndGetDigest() {
        // Given
        doNothing().when(messageBlock).setDigest(digest);
        when(messageBlock.getDigest()).thenReturn(digest);

        // When
        messageBlock.setDigest(digest);