public CredentialsInternal renew() {
            // Returns null to represent an implementation that could not renew
            return null;
        }
    }

    // Provide different implementation behaviors to a parameterized test
    static Stream<Arguments> implementations() {
        return Stream.of(Arguments.of("returns self", (Supplier<SmbRenewableCredentials>) SelfRenewingCreds::new, true, false),

        mockConfig = mock(Configuration.class);
        mockCredentials = mock(Credentials.class);
        mockTransportPool = mock(SmbTransportPool.class);

        // Set up mock behaviors
        when(mockContext.getConfig()).thenReturn(mockConfig);
        when(mockContext.getCredentials()).thenReturn(mockCredentials);
        when(mockContext.getTransportPool()).thenReturn(mockTransportPool);

import org.junit.jupiter.params.provider.MethodSource;
import org.mockito.Mockito;
import org.mockito.junit.jupiter.MockitoExtension;

/**
 * Tests for SMBProtocolDowngradeException covering all constructors and behaviors.
 */
@ExtendWith(MockitoExtension.class)
class SMBProtocolDowngradeExceptionTest {

    /**
     * Provides messages including edge cases (null and empty) for parameterized testing.
     */

import org.junit.jupiter.params.provider.ValueSource;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

/**
 * Tests for SmbFilenameFilter interface behaviors via simple implementations.
 * Each test creates a concrete filter to validate expected contract semantics
 * including normal operation, null handling, edge cases, and exception flow.
 */
@ExtendWith(MockitoExtension.class)

            assertTrue(consistentRequest.isSigningEnforced(), "Implementation should consistently return the same value");
        }
    }

    @Test
    @DisplayName("Test different implementations can have different behaviors")
    void testDifferentImplementations() {
        // Given
        SmbNegotiationRequest enforcedRequest = new TestSmbNegotiationRequest(true);

import org.junit.jupiter.api.Test;

import jcifs.RuntimeCIFSException;

/**
 * Optimized test for Transport class focusing on core functionality
 * with fast execution and comprehensive coverage of key behaviors.
 */
class TransportTest {

    private TestableTransport transport;

    /**
     * Minimal Transport implementation for testing core functionality
     */

            assertThrows(NullPointerException.class, () -> SmbEnumerationUtil.doEnum(null, "*", 0, null, null));
        }
    }

    @Nested
    @DisplayName("Wrapper behaviors")
    class WrapperBehaviorTests {

        @Test
        void resourceFilterWrapper_accept_falseForNonSmbFile_andNoDelegation() throws Exception {
            // Arrange

    @BeforeEach
    void setUp() {
        // Create a fresh pool instance for each test
        pool = new SmbTransportPoolImpl();

        // Setup default mock behaviors
        when(ctx.getConfig()).thenReturn(config);
        when(ctx.getNameServiceClient()).thenReturn(nameSvc);
        when(ctx.getCredentials()).thenReturn(creds);
        when(ctx.getTransportPool()).thenReturn(pool);

            assertEquals(type, sid.getType());
            assertEquals(text, sid.getTypeText());
        }

        @Test
        @DisplayName("getDomainName and getAccountName behaviors for unknown, domain, and user")
        void testNamesByType() {
            byte[] ident = new byte[] { 0, 0, 0, 0, 0, 5 };
            // Unknown: domainName derived from numeric SID, accountName = RID

    class MockBehaviorTests {

        @Test
        @DisplayName("Should verify all interface methods can be mocked")
        void testAllMethodsCanBeMocked() {
            // Setup all mock behaviors
            when(mockReferralData.getExpiration()).thenReturn(1000L);
            when(mockReferralData.getPathConsumed()).thenReturn(10);
            when(mockReferralData.getDomain()).thenReturn("domain");