// When
        byte[] decKey = Smb3KeyDerivation.deriveDecryptionKey(dialect, sessionKey, preauthIntegrity);

        // Then
        assertNotNull(decKey, "Decryption key should not be null");
        assertEquals(16, decKey.length, "Decryption key should be 16 bytes");
        assertFalse(Arrays.equals(sessionKey, decKey), "Decryption key should be different from session key");
    }

import java.io.IOException;
import java.io.OutputStream;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestByteSink extends ByteSink implements TestStreamSupplier {

  private final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
  private final ImmutableSet<TestOption> options;

        try {
            int expectedKeyLength = getKeyLength();
            byte[] encKey = getEncryptionKey();
            byte[] decKey = getDecryptionKey();

            try {
                boolean valid =
                        encKey != null && encKey.length == expectedKeyLength && decKey != null && decKey.length == expectedKeyLength;
                return valid;
            } finally {

        // Given
        byte[] encKey = new byte[16];
        byte[] decKey = new byte[16];
        new SecureRandom().nextBytes(encKey);
        new SecureRandom().nextBytes(decKey);

        // When using try-with-resources
        assertDoesNotThrow(() -> {
            try (Smb2EncryptionContext context = new Smb2EncryptionContext(1, DialectVersion.SMB311, encKey, decKey)) {
                assertNotNull(context, "Context should be created");

import java.io.IOException;
import java.io.InputStream;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte source for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public final class TestByteSource extends ByteSource implements TestStreamSupplier {

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

import java.io.IOException;
import java.io.InputStream;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte source for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public final class TestByteSource extends ByteSource implements TestStreamSupplier {

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

import java.util.Objects;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Closer}.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CloserTest extends TestCase {

  private TestSuppressor suppressor;

  @Override
  protected void setUp() throws Exception {
    suppressor = new TestSuppressor();
  }

import org.jspecify.annotations.Nullable;

/**
 * Abstract {@link Hasher} that handles converting primitives to bytes using a scratch {@code
 * ByteBuffer} and streams all bytes to a sink to compute the hash.
 *
 * @author Colin Decker
 */
abstract class AbstractByteHasher extends AbstractHasher {
  private @Nullable ByteBuffer scratch;

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

 * A generator of {@code TestSuite} instances for testing {@code CharSource} implementations.
 * Generates tests of all methods on a {@code CharSource} given various inputs the source is
 * expected to contain.
 *
 * @author Colin Decker
 */
@AndroidIncompatible // TODO(b/230620681): Make this available (even though we won't run it).
@NullUnmarked
public class CharSourceTester extends SourceSinkTester<CharSource, String, CharSourceFactory> {

import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Provides utility methods for working with character streams.
 *
 * @author Chris Nokleberg
 * @author Bin Zhu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;