import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A skeleton implementation of a descending multiset. Only needs {@code forwardMultiset()} and
 * {@code entryIterator()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
abstract class DescendingMultiset<E extends @Nullable Object> extends ForwardingMultiset<E>
    implements SortedMultiset<E> {

     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull
    static ToolchainsBuilderRequest build(
            @Nonnull Session session,
            @Nullable Source installationToolchainsFile,
            @Nullable Source userToolchainsSource) {
        return builder()
                .session(nonNull(session, "session cannot be null"))
                .installationToolchainsSource(installationToolchainsFile)

    final CountDownLatch isInterruptibleRegistered = new CountDownLatch(1);
    final SlowChannel slowChannel = new SlowChannel();
    final InterruptibleTask<@Nullable Void> task =
        new InterruptibleTask<@Nullable Void>() {
          @Override
          @Nullable Void runInterruptibly() throws Exception {
            slowChannel.doBegin();
            isInterruptibleRegistered.countDown();
            try {

                    @Nullable Project project,
                    @Nullable Artifact rootArtifact,
                    @Nullable DependencyCoordinates root,
                    @Nonnull Collection<DependencyCoordinates> dependencies,
                    @Nonnull Collection<DependencyCoordinates> managedDependencies,
                    boolean verbose,
                    @Nullable PathScope pathScope,

 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));
  }

      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsRow(rowKey);
    }

    @Override
    public @Nullable V get(Object rowKey, Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.get(rowKey, columnKey);
    }

    @Override
    public @Nullable V put(R rowKey, C columnKey, V value) {
      assertTrue(Thread.holdsLock(mutex));

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Derived suite generators, split out of the suite builders so that they are available to GWT.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class DerivedCollectionGenerators {
  public static class MapEntrySetGenerator<K extends @Nullable Object, V extends @Nullable Object>

})
abstract class AbstractTransformFuture<
        I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>
    extends FluentFuture.TrustedFuture<O> implements Runnable {
  static <I extends @Nullable Object, O extends @Nullable Object> ListenableFuture<O> createAsync(
      ListenableFuture<I> input,
      AsyncFunction<? super I, ? extends O> function,

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

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *

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

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *