// Then
            assertNotNull(cancel);
            assertEquals(mid, cancel.getMid());
        }

        @Test
        @DisplayName("Should throw NullPointerException when config is null")
        void testNullConfigurationThrowsException() throws Exception {
            // Given

        @DisplayName("Null delegate causes NullPointerException during construction")
        void nullDelegate_throwsNPE() throws Exception {
            SmbFile parent = newParent();
            assertThrows(NullPointerException.class, () -> new ShareEnumIterator(parent, null, null));
        }

        @Test
        @DisplayName("Null parent with non-empty iterator causes NullPointerException during adapt")

        NtlmHttpServletRequest request = new NtlmHttpServletRequest(mockRequest, null);

        // getRemoteUser() will throw NPE when trying to call getName() on null principal
        assertThrows(NullPointerException.class, () -> request.getRemoteUser());
        assertNull(request.getUserPrincipal());
        assertEquals("NTLM", request.getAuthType());
    }

    @Test

    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEYS)
  public void testPutIfAbsent_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

        method.setAccessible(true);

        // This should fail because localhost doesn't support SMB multi-channel
        // but the method should not throw NullPointerException
        try {
            method.invoke(multiChannelManager, localhost, loopback);
            // If it doesn't throw, that's unexpected for localhost

    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

    assertThrows(NullPointerException.class, () -> putAll(containsNullValue));
    expectUnchanged();
    expectNullValueMissingWhenNullValuesUnsupported(
        "Should not contain null value after unsupported putAll(containsNullValue)");
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll_nullCollectionReference() {
    assertThrows(NullPointerException.class, () -> getMap().putAll(null));
  }

        }
    }

    @Test
    void testNullHandling() {
        assertThrows(NullPointerException.class, () -> Sources.fromPath(null));
        assertThrows(NullPointerException.class, () -> Sources.buildSource(null));
        assertThrows(NullPointerException.class, () -> Sources.resolvedSource(null, "modelId"));
    }

    expectContents(expected);
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEYS)
  public void testPut_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> put(nullKeyEntry));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported put(null, value)");
  }

  public void testFind_nullNotContainedAndUnsupported() {
    try {
      assertEquals(getMethodName() + "(nullNotPresent) should return -1 or throw", -1, find(null));
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testFind_nonNullWhenNullContained() {
    initCollectionWithNullElement();