// Should write a benchmark to test that!
    Map<Element, Element> map = mapToTest;
    Element[] queries = this.queries;

    // Allows us to use & instead of %, acting on hearsay that division
    // operators (/%) are disproportionately expensive; should test this too!
    int mask = queries.length - 1;

    boolean dummy = false;
    for (int i = 0; i < reps; i++) {
      dummy ^= map.get(queries[i & mask]) != null;

    // Should write a benchmark to test that!
    Map<Element, Element> map = mapToTest;
    Element[] queries = this.queries;

    // Allows us to use & instead of %, acting on hearsay that division
    // operators (/%) are disproportionately expensive; should test this too!
    int mask = queries.length - 1;

    boolean dummy = false;
    for (int i = 0; i < reps; i++) {
      dummy ^= map.get(queries[i & mask]) != null;

 * creation methods appear to adhere doggedly to the original intent of the "mapped" address: all
 * "mapped" addresses return {@link Inet4Address} objects.
 *
 * <p>For added safety, it is common for IPv6 network operators to filter all packets where either
 * the source or destination address appears to be a "compat" or "mapped" address. Filtering
 * suggestions usually recommend discarding any packets with source or destination addresses in the

    Iterator<String> itr2 = Iterators.concat(Iterators.singletonIterator("d"), itr1);
    assertEquals("d", itr2.next());
    assertEquals("c", itr2.next());
  }

  public void testConcatPartiallyAdvancedFirst() {
    Iterator<String> itr1 =
        Iterators.concat(Iterators.singletonIterator("a"), Iterators.forArray("b", "c"));
    assertEquals("a", itr1.next());
    assertEquals("b", itr1.next());

    checkNotNull(iterable);
    Iterators.checkNonnegative(position);
    if (iterable instanceof List) {
      List<? extends T> list = Lists.cast(iterable);
      return (position < list.size()) ? list.get(position) : defaultValue;
    } else {
      Iterator<? extends T> iterator = iterable.iterator();
      Iterators.advance(iterator, position);
      return Iterators.getNext(iterator, defaultValue);
    }
  }

  public Entry<K, V> firstEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(entryIterator(), null);
  }

  @Override
  @CheckForNull
  public Entry<K, V> lastEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(descendingEntryIterator(), null);
  }

  @Override
  @CheckForNull
  public Entry<K, V> pollFirstEntry() {
    return Iterators.pollNext(entryIterator());
  }

  @Override

      } catch (UnsupportedOperationException expected) {
      }
    }
  }

  /**
   * Asserts that two iterators contain elements in tandem.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorsInOrder(
      Iterator<?> expectedIterator, Iterator<?> actualIterator) {
    int i = 0;

import static com.google.common.graph.GraphConstants.INNER_CAPACITY;
import static com.google.common.graph.GraphConstants.INNER_LOAD_FACTOR;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterators;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import javax.annotation.CheckForNull;

/**

  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    Set<String> set = copyOf(iterator);
    assertEquals(Collections.<String>emptySet(), set);
    assertSame(this.<String>of(), set);
  }

  public void testCopyOf_iterator_oneElement() {
    Iterator<String> iterator = Iterators.singletonIterator("a");
    Set<String> set = copyOf(iterator);

  }

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    Set<String> set = copyOf(iterator);
    assertEquals(Collections.<String>emptySet(), set);
    assertSame(this.<String>of(), set);
  }

  public void testCopyOf_iterator_oneElement() {
    Iterator<String> iterator = Iterators.singletonIterator("a");
    Set<String> set = copyOf(iterator);