import java.io.InputStream;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

/**
 * An {@link InputStream} that concatenates multiple substreams. At most one stream will be open at
 * a time.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class MultiInputStream extends InputStream {

  private final Iterator<? extends ByteSource> it;

  }

  /**
   * A sensible definition of {@link #pollFirst} in terms of the {@code iterator} method. If you
   * override {@link #iterator} you may wish to override {@link #pollFirst} to forward to this
   * implementation.
   */
  protected @Nullable E standardPollFirst() {
    return Iterators.pollNext(iterator());
  }

  @Override
  public @Nullable E pollLast() {
    return delegate().pollLast();

        assertThat(lru.get("aaa"), is("111"));
        Iterator<String> i = lru.keySet().iterator();
        assertThat(i.next(), is("bbb"));
        assertThat(i.next(), is("ccc"));
        assertThat(i.next(), is("aaa"));
        lru.put("ddd", "444");
        assertThat(lru.size(), is(3));
        assertThat(lru.get("bbb"), is(nullValue()));
        i = lru.keySet().iterator();
        assertThat(i.next(), is("ccc"));

    return Reflection.newProxy(List.class, new DelegatingInvocationHandlerWithEquals(delegate));
  }

  @SuppressWarnings("unchecked") // proxy of Iterable<String>
  private static Iterable<String> newDelegatingIterableWithEquals(Iterable<String> delegate) {
    return Reflection.newProxy(Iterable.class, new DelegatingInvocationHandlerWithEquals(delegate));
  }

  @SuppressWarnings("unchecked") // proxy of List<String>

  private final SpecialRandom random;
  private final double hitRate;
  private final int size;

  private final Set<Element> valuesInSet;
  private final Element[] queries;

  CollectionBenchmarkSampleData(int size) {
    this(true, new SpecialRandom(), 1.0, size);
  }

  CollectionBenchmarkSampleData(
      boolean isUserTypeFast, SpecialRandom random, double hitRate, int size) {
    this.isUserTypeFast = isUserTypeFast;

    assertEqualInOrder(expected, multimap().values());
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(ONE)
  public void testValuesIteratorRemove() {
    Iterator<V> valuesItr = multimap().values().iterator();
    valuesItr.next();
    valuesItr.remove();
    assertTrue(multimap().isEmpty());
  }

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotMock;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * An iterator that supports a one-element lookahead while iterating.
 *
 * <p>See the Guava User Guide article on <a href=

        Set set = project1.getArtifacts();
        assertNotNull(set, "No artifacts");
        assertFalse(set.isEmpty(), "No Artifacts");
        Iterator iter = set.iterator();
        assertTrue(set.size() == 4, "Set size should be 4, is " + set.size());

        while (iter.hasNext()) {
            Artifact artifact = (Artifact) iter.next();

     */
    public CaseInsensitiveSet(final int initialCapacity) {
        map = new CaseInsensitiveMap<>(initialCapacity);
    }

    @Override
    public Iterator<String> iterator() {
        return map.keySet().iterator();
    }

    @Override
    public int size() {
        return map.size();
    }

    @Override
    public boolean isEmpty() {
        return map.isEmpty();
    }

    return delegate.higher(checkValid(e));
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override
  public Iterator<E> iterator() {
    return delegate.iterator();
  }

  @Override
  public E last() {
    return delegate.last();
  }

  @Override
  public @Nullable E lower(E e) {
    return delegate.lower(checkValid(e));
  }