if (num >= 0) {
      Object[] rest = new Integer[num];
      for (int i = 0; i < num; i++) {
        rest[i] = partsArray[i + 2];
      }

      assertEquals(expected, joiner.join(partsArray[0], partsArray[1], rest));

      StringBuilder sb3 = new StringBuilder().append('x');
      joiner.appendTo(sb3, partsArray[0], partsArray[1], rest);
      assertEquals("x" + expected, sb3.toString());
    }

API changes
-----------

We make changes to Guava's public [APIs][], including adding new APIs, very
carefully. Because of this, if you're interested in seeing a new feature in
Guava, the best approach is to create an [issue][] (or comment on an existing
issue if there is one) requesting the feature and describing specific use cases
for it.

If the feature has merit, it will go through a thorough process of API design

import com.google.common.testing.EqualsTester;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.Set;
import junit.framework.Test;
import junit.framework.TestSuite;

/**
 * Unit test for {@link ImmutableSet}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @author Nick Kralevich
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault

   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is non-null; {@code ""} if it is null
   */
  public static String nullToEmpty(@CheckForNull String string) {
    return Platform.nullToEmpty(string);
  }

  /**
   * Returns the given string if it is nonempty; {@code null} otherwise.
   *
   * @param string the string to test and possibly return

   * previously at {@code src} has already been removed from the data structures.
   */
  private void moveEntryToIndex(int src, int dest) {
    if (src == dest) {
      return;
    }
    int predecessor = prevInInsertionOrder[src];
    int successor = nextInInsertionOrder[src];
    setSucceeds(predecessor, dest);
    setSucceeds(dest, successor);

    assertEquals(""test"", htmlEscaper().escape("\"test\""));
    assertEquals("'test'", htmlEscaper().escape("\'test'"));
    assertEquals("test & test & test", htmlEscaper().escape("test & test & test"));
    assertEquals("test &lt;&lt; 1", htmlEscaper().escape("test << 1"));
    assertEquals("test &gt;&gt; 1", htmlEscaper().escape("test >> 1"));

   */
  public static HashFunction concatenating(
      HashFunction first, HashFunction second, HashFunction... rest) {
    // We can't use Lists.asList() here because there's no hash->collect dependency
    List<HashFunction> list = new ArrayList<>();
    list.add(first);
    list.add(second);
    Collections.addAll(list, rest);
    return new ConcatenatedHashFunction(list.toArray(new HashFunction[0]));
  }

  /**

      }
    }.test();
  }

  @GwtIncompatible // slow (~30s)
  public void testIterator_general() {
    new IteratorTester<String>(
        5, UNMODIFIABLE, asList("a", "b", "c"), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<String> newTargetIterator() {
        return of("a", "b", "c").iterator();
      }
    }.test();
  }

      }
    }.test();
  }

  @GwtIncompatible // slow (~30s)
  public void testIterator_general() {
    new IteratorTester<String>(
        5, UNMODIFIABLE, asList("a", "b", "c"), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<String> newTargetIterator() {
        return of("a", "b", "c").iterator();
      }
    }.test();
  }

      createDirectedGraph("ab", "fe", "fg", "bc", "bd", "ed", "eh", "gh");

  @Test
  public void forGraph_breadthFirst_javadocExample_canBeIteratedMultipleTimes() {
    Iterable<Character> result = Traverser.forGraph(JAVADOC_GRAPH).breadthFirst('a');

    assertEqualCharNodes(result, "abcdef");
    assertEqualCharNodes(result, "abcdef");
  }

  @Test