assertNull(ex.getMessage(), "Default ctor should not set a message");
        assertNull(ex.getCause(), "Default ctor should not set a cause");
        assertTrue(ex instanceof SmbException, "Should be an SmbException subtype");
        // SmbException default ctor leaves status 0, which equals NT_STATUS_SUCCESS
        assertEquals(NtStatus.NT_STATUS_SUCCESS, ex.getNtStatus(), "Default status should be success (0)");
    }

#495057;\n  --bs-dark-text-emphasis: #495057;\n  --bs-primary-bg-subtle: #cfe2ff;\n  --bs-secondary-bg-subtle: #e2e3e5;\n  --bs-success-bg-subtle: #d1e7dd;\n  --bs-info-bg-subtle: #cff4fc;\n  --bs-warning-bg-subtle: #fff3cd;\n  --bs-danger-bg-subtle: #f8d7da;\n  --bs-light-bg-subtle: #fcfcfd;\n  --bs-dark-bg-subtle: #ced4da;\n  --bs-primary-border-subtle: #9ec5fe;\n  --bs-secondary-border-subtle: #c4c8cb;\n  --bs-success-border-subtle: #a3cfbb;\n  --bs-info-border-subtle: #9eeaf9;\n  --bs-warning-border-subtle:...

        String result = StringUtil.join(",", "z", "y", "x", "w", "v");
        assertEquals("z,y,x,w,v", result);
    }

    @Test
    @DisplayName("Should handle delimiter as CharSequence subtype")
    void testJoinWithCharSequenceDelimiter() {
        StringBuilder delimiter = new StringBuilder(" | ");
        String result = StringUtil.join(delimiter, "one", "two");
        assertEquals("one | two", result);

            result[ri] = "";
            ri++;
        }
    }

    DfsReferral getDfsReferrals(final NtlmPasswordAuthentication auth, final String path, int rn) throws SmbException {
        final SmbTree ipc = getSmbSession(auth).getSmbTree("IPC$", null);
        final Trans2GetDfsReferralResponse resp = new Trans2GetDfsReferralResponse();
        ipc.send(new Trans2GetDfsReferral(path), resp);

                assertTrue(SmbSession.class.isAssignableFrom((Class<?>) unwrapMethod.getReturnType()),
                        "unwrap method should return SmbSession or subtype");
            }, "unwrap(Class) method should be properly defined");
        }

        @Test
        @DisplayName("Should handle unwrap with SmbSession type")
        void shouldHandleUnwrapWithSmbSessionType() {

@Override
public void logoff() throws IOException {
    if (witnessClient != null) {
        witnessClient.close();
    }
    super.logoff();
}
```

### 5.2 Tree Connection Integration
```java
// In SmbTree.java
public void connectWithWitnessSupport() throws IOException {
    // Perform normal tree connection
    super.connect();
    
    // Register for witness notifications for this share

          <match value="0x0006" type="little32" offset="16"/>
      </match>
    </magic>
    <sub-class-of type="application/x-berkeley-db;format=btree"/>
  </mime-type>
  <mime-type type="application/x-berkeley-db;format=btree;version=3">
    <_comment>Berkeley DB Version 3 BTree Database</_comment>
    <magic priority="60">
      <match value="0x00053162" type="host32" offset="12">

    /**
     * DFS resolver instance
     */
    protected static Dfs dfs;

    NtlmPasswordAuthentication auth; // Cannot be null
    SmbTree tree = null; // Initially null
    String unc; // Initially null; set by getUncPath; never ends with '/'
    int fid; // Initially 0; set by open()
    int type;
    boolean opened;
    int tree_num;

    /**