verifyNoInteractions(mockCause);
    }

    @Test
    @DisplayName("Cause-only constructor with null: null cause maintained")
    void causeOnlyConstructor_acceptsNull() {
        // Arrange & Act
        SMBProtocolDecodingException ex = new SMBProtocolDecodingException((Throwable) null);

        // Assert
        assertNull(ex.getCause(), "Null cause should be preserved");