return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }

  @VisibleForTesting
  @SuppressWarnings("GoodTime") // lots of violations
  static final class ExpiringMemoizingSupplier<T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    private transient Object lock = new Object();

    final Supplier<T> delegate;

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit tests for {@link Invokable}.
 *
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
@NullUnmarked
public class InvokableTest extends TestCase {
  // Historically Invokable inherited from java.lang.reflect.AccessibleObject. That's no longer the

  /**
   * This is a less carefully-controlled version of {@link #testRemovalNotification_clear} - this is
   * a black-box test that tries to create lots of different thread-interleavings, and asserts that
   * each computation is affected by a call to {@code clear()} (and therefore gets passed to the

  /**
   * This is a less carefully-controlled version of {@link #testRemovalNotification_clear} - this is
   * a black-box test that tries to create lots of different thread-interleavings, and asserts that
   * each computation is affected by a call to {@code clear()} (and therefore gets passed to the

      assertThat(out).isSameInstanceAs(in);
    } else {
      assertThat(out).isEqualTo(expected);
    }
  }

  // Test collapse() a little differently than the rest, as we really want to
  // cover lots of different configurations of input text
  public void testCollapse() {
    // collapsing groups of '-' into '_' or '-'
    doTestCollapse("-", "_");
    doTestCollapse("x-", "x_");
    doTestCollapse("-x", "_x");

      }
    }
  }

  /*
   * This next part consists of several sample classes that provide
   * demonstrations of conditions that cause NullPointerTester
   * to succeed/fail.
   */

  /** Lots of well-behaved methods. */
  @SuppressWarnings("unused") // used by reflection
  private static class PassObject extends SomeClassThatDoesNotUseNullable {
    @Keep
    public static void doThrow(Object arg) {

    assertThat(hpackReader!!.headerCount).isEqualTo(1)
  }

  /** Header table backing array is initially 8 long, let's ensure it grows.  */
  @Test
  fun dynamicallyGrowsBeyond64Entries() {
    // Lots of headers need more room!
    hpackReader = Hpack.Reader(bytesIn, 16384, 4096)
    bytesIn.writeByte(0x3F) // Dynamic table size update (size = 16384).
    bytesIn.writeByte(0xE1)
    bytesIn.writeByte(0x7F)

REST tests to test integration.

==== Refactor code to make it easier to test

Unfortunately, a large part of our code base is still hard to unit test.
Sometimes because some classes have lots of dependencies that make them hard to
instantiate. Sometimes because API contracts make tests hard to write. Code
refactors that make functionality easier to unit test are encouraged. If this

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Test cases for {@link TypeToken}.
 *
 * @author Sven Mawson
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
@NullUnmarked
public class TypeTokenTest extends TestCase {

  private abstract static class StringList implements List<String> {}

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Test cases for {@link TypeToken}.
 *
 * @author Sven Mawson
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
@NullUnmarked
public class TypeTokenTest extends TestCase {

  private abstract static class StringList implements List<String> {}