*
   * <p>This differs from {@code Long.bitCount(x) == 1}, because {@code
   * Long.bitCount(Long.MIN_VALUE) == 1}, but {@link Long#MIN_VALUE} is not a power of two.
   */
  // Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
  @SuppressWarnings("ShortCircuitBoolean")
  public static boolean isPowerOfTwo(long x) {
    return x > 0 & (x & (x - 1)) == 0;
  }

  /**

            // The rate limiter should still be functional after concurrent access
            assertTrue(concurrentLimiter.checkAttempt("finaluser", "192.168.3.1"),
                    "Rate limiter should still be functional after concurrent operations");

            // Verify that the rate limiter tracked some activity

      extends AbstractTransformFuture<I, O, Function<? super I, ? extends O>, O> {
    TransformFuture(
        ListenableFuture<? extends I> inputFuture, Function<? super I, ? extends O> function) {
      super(inputFuture, function);
    }

    @Override
    @ParametricNullness
    O doTransform(Function<? super I, ? extends O> function, @ParametricNullness I input) {
      return function.apply(input);
    }

    @Override

      extends AbstractTransformFuture<I, O, Function<? super I, ? extends O>, O> {
    TransformFuture(
        ListenableFuture<? extends I> inputFuture, Function<? super I, ? extends O> function) {
      super(inputFuture, function);
    }

    @Override
    @ParametricNullness
    O doTransform(Function<? super I, ? extends O> function, @ParametricNullness I input) {
      return function.apply(input);
    }

    @Override

            throw (IOException) lastError;
        } else {
            throw new IOException("RDMA operation failed after " + (retryCount + 1) + " attempts", lastError);
        }
    }

    /**
     * Functional interface for RDMA operations that can be retried
     *
     * @param <T> the type of result returned by the operation
     */
    @FunctionalInterface
    public interface RdmaOperation<T> {
        /**

        @Override
        public long length() {
            return length;
        }

        @Override
        public int getFileIndex() {
            return fileIndex;
        }
    }

    // Functional helpers for concise parameterized tests
    private interface IntGetter {
        int apply(FileEntry e);
    }

    private interface LongGetter {
        long apply(FileEntry e);
    }

### Infrastructure
- Windows Server test lab
- RDMA-capable test hardware
- Continuous integration environment
- Performance testing infrastructure

## Success Metrics

1. **Functional Completeness**: All features pass Windows Protocol Test Suite
2. **Performance**: 
   - Multi-channel provides >1.5x throughput improvement
   - RDMA reduces latency by >50%
3. **Reliability**: 

    CacheBuilder<Object, Object> builder = CacheBuilder.from(parse("maximumSize=9000"));
    builder.build(CacheLoader.from(Suppliers.ofInstance(null)));
  }

  public void testDisableCaching() {
    // Functional test: assert that CacheBuilderSpec.disableCaching()
    // disables caching.  It's irrelevant how it does so.
    CacheBuilder<Object, Object> builder = CacheBuilder.from(CacheBuilderSpec.disableCaching());

        try {
            SearchEngineUtil.class.getMethod("scroll", String.class, java.util.function.Function.class);
        } catch (NoSuchMethodException e) {
            fail("scroll method should exist with correct signature");
        }
    }

    public void test_XContentBuilderCallback_interface() {
        // Test that the functional interface works correctly
        XContentBuilderCallback callback = (builder, params) -> {

 *
 * This test class verifies the basic functionality of DirFileEntryAdapterIterator.
 * Due to the iterator's constructor calling advance() immediately, which requires
 * the adapt() method to be functional, we test the behavior using simple mock
 * scenarios that don't require complex filter setups.
 */
@ExtendWith(MockitoExtension.class)
class DirFileEntryAdapterIteratorTest {

    @Mock