assertEquals("get(present) should return the associated value", v0(), get(k0()));
  }

  public void testGet_no() {
    assertNull("get(notPresent) should return null", get(k3()));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testGet_nullNotContainedButAllowed() {
    assertNull("get(null) should return null", get(null));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)

        }
        try (final ResponseData responseData = s3Client.doHead("s3://fess/")) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = s3Client.doHead("s3://fess/dir1/")) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = s3Client.doHead("s3://fess/dir1/dir2/")) {

    }

    public void test_normalize_null() {
        String enc;

        enc = null;
        assertNull(encodingHelper.normalize(enc));

        enc = "";
        assertNull(encodingHelper.normalize(enc));

        enc = " ";
        assertNull(encodingHelper.normalize(enc));
    }

    public void test_normalize_default() {
        String enc;

        assertNull(dfsImpl.getDc(mockContext, "anydomain.com"));
    }

    @Test
    void testGetDc_ConnectionFails() throws SmbAuthException {
        // Scenario: Transport connection fails when getting DC
        when(mockCredentials.getUserDomain()).thenReturn("authdomain.com");
        // When transport fails to connect, getDc returns null
        assertNull(dfsImpl.getDc(mockContext, "anydomain.com"));

    void testDefaultConstructor() {
        // Given & When
        CIFSUnsupportedCryptoException exception = new CIFSUnsupportedCryptoException();

        // Then
        assertNull(exception.getMessage(), "Default constructor should have null message");
        assertNull(exception.getCause(), "Default constructor should have null cause");
        assertTrue(exception instanceof RuntimeCIFSException, "Should extend RuntimeCIFSException");

  @CollectionSize.Require(ZERO)
  public void testEmptySetPollFirst() {
    assertNull(navigableSet.pollFirst());
  }

  @CollectionSize.Require(ZERO)
  public void testEmptySetNearby() {
    assertNull(navigableSet.lower(e0()));
    assertNull(navigableSet.floor(e0()));
    assertNull(navigableSet.ceiling(e0()));
    assertNull(navigableSet.higher(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

        assertNull(auth1.getPassword());

        // Test with null char[] password
        NtlmPasswordAuthenticator auth2 = new NtlmPasswordAuthenticator("testuser", (char[]) null);
        assertNull(auth2.getPassword());

        // Test secure wipe on null password
        auth1.secureWipePassword(); // Should not throw exception
        assertNull(auth1.getPassword());
    }

    /**

        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");