MoreFiles.touch(temp);
    assertThat(Files.getLastModifiedTime(temp).toMillis()).isNotEqualTo(0);
  }

  public void testCreateParentDirectories_root() throws IOException {
    // We use a fake filesystem to sidestep flaky problems with Windows (b/136041958).
    try (FileSystem fs = Jimfs.newFileSystem(Configuration.unix())) {
      Path root = fs.getRootDirectories().iterator().next();

     * Given that we declare this method as accepting and returning non-nullable values (because we
     * implement Function<A, B>, as discussed in a class-level comment), it would make some sense to
     * perform runtime null checks on the input and output. (That would also make NullPointerTester
     * happy!) However, since we didn't do that for many years, we're not about to start now.

      list.add(i);
    }

    Ordering<Object> arbitrary =
        new ArbitraryOrdering() {
          @Override
          int identityHashCode(Object object) {
            return ((Integer) object) % 5; // fake tons of collisions!
          }
        };

    // Don't let the elements be in such a predictable order
    list = shuffledCopy(list, new Random(1));

    Collections.sort(list, arbitrary);

      list.add(i);
    }

    Ordering<Object> arbitrary =
        new ArbitraryOrdering() {
          @Override
          int identityHashCode(Object object) {
            return ((Integer) object) % 5; // fake tons of collisions!
          }
        };

    // Don't let the elements be in such a predictable order
    list = shuffledCopy(list, new Random(1));

    Collections.sort(list, arbitrary);

     * Given that we declare this method as accepting and returning non-nullable values (because we
     * implement Function<A, B>, as discussed in a class-level comment), it would make some sense to
     * perform runtime null checks on the input and output. (That would also make NullPointerTester
     * happy!) However, since we didn't do that for many years, we're not about to start now.

 * An implementation of {@code Iterable} which throws an exception on all invocations of the {@link
 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again
 *   <li>throwing an exception of some kind

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** Implementation of {@link Futures#immediateFuture}. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class ImmediateFuture<V extends @Nullable Object> implements ListenableFuture<V> {
  static final ListenableFuture<?> NULL = new ImmediateFuture<@Nullable Object>(null);

import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Tester to make sure the {@code iterator().remove()} implementation of {@code Multiset} works when
 * there are multiple occurrences of elements.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(emulated = true)

   *     class under test.
   */
  protected abstract Map<K, V> makeEmptyMap() throws UnsupportedOperationException;

  /**
   * Creates a new, non-empty instance of the class under test.
   *
   * @return a new, non-empty map instance.
   * @throws UnsupportedOperationException if it's not possible to make a non-empty instance of the
   *     class under test.

      }

      @Override
      public <T> T[] toArray(T[] a) {
        toArrayCalled = true;
        return super.toArray(a);
      }
    }

    // Test that toArray() is used to make a defensive copy in copyOf(), so concurrently modified
    // synchronized collections can be safely copied.
    TestArrayList<String> toCopy = new TestArrayList<>();
    ImmutableSortedMultiset<String> unused =