Kerb5Authenticator auth = new Kerb5Authenticator((Subject) null);

        // User accessors
        assertNull(auth.getUser());
        auth.setUser(null);
        assertNull(auth.getUser());
        auth.setUser("");
        assertEquals("", auth.getUser());

        // Realm accessors
        assertNull(auth.getRealm());
        auth.setRealm("EXAMPLE.COM");
        assertEquals("EXAMPLE.COM", auth.getRealm());

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.Mockito.mock;

        // Arrange & Act
        SMBProtocolDecodingException ex = new SMBProtocolDecodingException();

        // Assert state
        assertNull(ex.getMessage(), "Default constructor should have null message");
        assertNull(ex.getCause(), "Default constructor should have null cause");
        assertTrue(ex instanceof CIFSException, "Should be a CIFSException subtype");

    for (BoundType type : BoundType.values()) {
      assertNull(sortedMultiset.headMultiset(e0(), type).lastEntry());
      assertNull(sortedMultiset.tailMultiset(e0(), type).firstEntry());
    }
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetLast() {
    assertNull(sortedMultiset.lastEntry());
    assertThrows(
        NoSuchElementException.class, () -> assertNull(sortedMultiset.elementSet().last()));
  }

import okhttp3.internal.platform.android.StandardAndroidSocketAdapter
import org.conscrypt.Conscrypt
import org.junit.Assert.assertFalse
import org.junit.Assert.assertNotNull
import org.junit.Assert.assertNull
import org.junit.Assert.assertTrue
import org.junit.Assume.assumeFalse
import org.junit.Assume.assumeTrue
import org.junit.Test
import org.junit.runner.RunWith
import org.robolectric.ParameterizedRobolectricTestRunner

    try {
      assertNull(
          "remove(null) should return null or throw NullPointerException", getMap().remove(null));
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEY_QUERIES})
  public void testRemove_nullSupportedMissing() {
    assertNull("remove(null) should return null", getMap().remove(null));

        assertNull(smbAuthenticationHolder.get(null));
        assertNull(smbAuthenticationHolder.get(""));
        assertNull(smbAuthenticationHolder.get(" "));
        assertNull(smbAuthenticationHolder.get("smb://"));
        assertNull(smbAuthenticationHolder.get("smb://hoge:1000/"));
        assertNull(smbAuthenticationHolder.get("smb://foo/"));
        assertNull(smbAuthenticationHolder.get("smb://foo:10000/"));

        NegTokenInit parsed = new NegTokenInit(bytes);
        assertNull(parsed.getMechanisms(), "Mechanisms should be null when absent");
        assertEquals(0, parsed.getContextFlags(), "Flags should be zero when absent");
        assertNull(parsed.getMechanismToken(), "Mechanism token should be null when absent");
        assertNull(parsed.getMechanismListMIC(), "MIC should be null when absent");
    }

    @Test

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertInstanceOf;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;

            assertNull(context.getHashAlgos());
            assertNull(context.getSalt());
        }

        @Test
        @DisplayName("Should handle null hash algorithms")
        void testNullHashAlgorithms() {
            context = new PreauthIntegrityNegotiateContext(mockConfig, null, new byte[16]);

            assertNull(context.getHashAlgos());