private transient Object lock = new Object();

    final Supplier<T> delegate;
    final long durationNanos;
    transient volatile @Nullable T value;
    // The special value 0 means "not yet initialized".
    transient volatile long expirationNanos;

    ExpiringMemoizingSupplier(Supplier<T> delegate, long durationNanos) {
      this.delegate = delegate;
      this.durationNanos = durationNanos;

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

  //
  // A wrinkle here is that the value 0 (called UNSET in the code) is used as the equivalent of a
  // null pointer. If `table[h] == 0` that means there are no keys in the map whose short hash is h.
  // If the `next` bits in `entries[i]` are 0 that means there are no further entries for the given
  // short hash. But 0 is also a valid index in `entries`, so we add 1 to these indices before

        statusLine.code == HTTP_CONTINUE -> {
          state = STATE_READ_RESPONSE_HEADERS
          responseBuilder
        }
        statusLine.code in (102 until 200) -> {
          // Processing and Early Hints will mean a second headers are coming.
          // Treat others the same for now
          state = STATE_READ_RESPONSE_HEADERS
          responseBuilder
        }
        else -> {
          state = STATE_OPEN_RESPONSE_BODY

 *
 * <p>The returned cache implements all optional operations of the {@link LoadingCache} and {@link
 * Cache} interfaces. The {@code asMap} view (and its collection views) have <i>weakly consistent
 * iterators</i>. This means that they are safe for concurrent use, but if other threads modify the
 * cache after the iterator is created, it is undefined which of these changes, if any, are

   * <p>The returned table is not thread-safe or serializable, even if the underlying table is.
   *
   * <p>The function is applied lazily, invoked when needed. This is necessary for the returned
   * table to be a view, but it means that the function will be applied many times for bulk
   * operations like {@link Table#containsValue} and {@code Table.toString()}. For this to perform

        assertEquals(26, written);

        // Check that padding bytes are zeros
        // The implementation writes 8 bytes with writeInt8 but only increments by 6
        // This means bytes 20-27 will be zero (8 bytes written by writeInt8)
        for (int i = 20; i < 28; i++) {
            assertEquals(0, buffer[i], "Padding byte at position " + i + " should be 0");
        }

                throw new NoSuchElementException();
              }
              i++;
              /*
               * The cast is safe because of the containsKey check in hasNext(). (That means it's
               * unsafe under concurrent modification, but all bets are off then, anyway.)
               */
              return uncheckedCastNullableTToT(map.get(key));
            }

                  + "determined after "
                  + count
                  + " trials.");
        }
      }
    }
  }

  /**
   * Test for avalanche. Avalanche means that output bits differ with roughly 1/2 probability on
   * different input keys. This test verifies that each possible 1-bit key delta achieves avalanche.
   *

    // "intermediate_ca" as the good CA. This signs a rogue certificate for localhost. The server
    // serves the good CAs certificate in the chain, which means the certificate pinner sees a
    // different set of certificates than the SSL verifier.
    val compromisedIntermediateCa =
      HeldCertificate
        .Builder()
        .signedBy(compromisedRootCa)