}
                if (selected == null) {
                    selected = type;
                } else if (unknown) {
                    // More than one filtered value, and we don't know how to handle at least one of them.
                    // TODO: add a plugin mechanism for allowing plugin to specify their selection algorithm.
                    return Optional.empty();
                }
            }

        A result(Collector<T, A, R> collector, Iterable<T> inputs);
  }

  /**
   * Verifies that the specified expected result is always produced by collecting the specified
   * inputs, regardless of how the elements are divided.
   */
  @SafeVarargs
  @CanIgnoreReturnValue
  @SuppressWarnings("nullness") // TODO(cpovirk): Remove after we fix whatever the bug is.

import java.util.Map;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Base class for map testers.
 *
 * <p>TODO: see how much of this is actually needed once Map testers are written. (It was cloned
 * from AbstractCollectionTester.)
 *
 * @param <K> the key type of the map to be tested.
 * @param <V> the value type of the map to be tested.

 * and semantically represents a known <i>kind</i> of dependency.
 * <p>
 * It provides information about the file type (or extension) of the associated artifact,
 * its default classifier, and how the artifact will be used in the build when creating
 * class-paths or module-paths.
 * <p>
 * For example, the type {@code java-source} has a {@code jar} extension and a

import org.eclipse.aether.repository.RemoteRepository;
import org.slf4j.LoggerFactory;

// TODO the antrun plugin has its own configurator, the only plugin that does. might need to think about how that works
// TODO remove the coreArtifactFilterManager

/**
 * DefaultBuildPluginManager
 */
@Named
@Singleton
public class DefaultBuildPluginManager implements BuildPluginManager {

   * values are null. This method may update {@code alternatingKeysAndValues} if there are duplicate
   * keys. If so, the return value will indicate how many entries are still valid, and will also
   * include a {@link Builder.DuplicateKey} in case duplicate keys are not allowed now or will not
   * be allowed on a later {@link Builder#buildOrThrow()} call.
   *

 *   }
 * } else {
 *   // do other things since the monitor was not available
 * }
 * }</pre>
 *
 * <h2>Comparison with {@code synchronized} and {@code ReentrantLock}</h2>
 *
 * <p>The following examples show a simple threadsafe holder expressed using {@code synchronized},
 * {@link ReentrantLock}, and {@code Monitor}.
 *
 * <h3>{@code synchronized}</h3>
 *

   *     minValue()}
   */
  @CheckForNull
  public abstract C previous(C value);

  /**
   * Returns a signed value indicating how many nested invocations of {@link #next} (if positive) or
   * {@link #previous} (if negative) are needed to reach {@code end} starting from {@code start}.

/** Tests the package level *impl methods directly using various types of lists. */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class ListsImplTest extends TestCase {

  /** Describes how a list is modifiable */
  public enum Modifiability {
    NONE, // immutable lists
    BY_ELEMENT, // elements can change (set), but not structure

   * 1] < [1, 2] < [2]}.
   *
   * <p>Note that {@code Collections.reverseOrder(lexicographical(comparator))} is not equivalent to
   * {@code lexicographical(Collections.reverseOrder(comparator))} (consider how each would order
   * {@code [1]} and {@code [1, 1]}).
   */
  // Note: 90% of the time we don't add type parameters or wildcards that serve only to "tweak" the