* them as a {@link String}. Example:
 *
 * <pre>{@code
 * Joiner joiner = Joiner.on("; ").skipNulls();
 *  . . .
 * return joiner.join("Harry", null, "Ron", "Hermione");
 * }</pre>
 *
 * <p>This returns the string {@code "Harry; Ron; Hermione"}. Note that all input elements are
 * converted to strings using {@link Object#toString()} before being appended.
 *

/**
 * Useful suppliers.
 *
 * <p>All methods return serializable suppliers as long as they're given serializable parameters.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Suppliers {
  private Suppliers() {}

  /**

        /*
         * a * b == aHi * bHi * 2^64 + (aHi * bLo + aLo * bHi) * 2^32 + aLo * bLo.
         *       == (aHi * bHi * 2^32 + aHi * bLo + aLo * bHi) * 2^32 + aLo * bLo
         *
         * We carry out this computation in modular arithmetic. Since times2ToThe32Mod accepts any
         * unsigned long, we don't have to do a mod on every operation, only when intermediate
         * results can exceed 2^63.
         */

    assertTrue("Heap is not intact initially", mmHeap.isIntact());
    assertEquals("bar", mmHeap.peek());
    assertEquals("sergey", mmHeap.peekLast());
    assertEquals(7, mmHeap.size());
    assertTrue("Could not remove larry", mmHeap.remove("larry"));
    assertEquals(6, mmHeap.size());
    assertFalse("heap contains larry which has been removed", mmHeap.contains("larry"));

      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and

    return suite;
  }

  Set<String> friends;
  Set<String> enemies;

  @Override
  public void setUp() {
    friends = Sets.newHashSet("Tom", "Joe", "Dave");
    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests com.google.common.base.Suppliers.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 */
@ElementTypesAreNonnullByDefault
@GwtCompatible(emulated = true)
public class SuppliersTest extends TestCase {

  static class CountingSupplier implements Supplier<Integer> {
    int calls = 0;

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests com.google.common.base.Suppliers.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 */
@ElementTypesAreNonnullByDefault
@GwtCompatible(emulated = true)
public class SuppliersTest extends TestCase {

  static class CountingSupplier implements Supplier<Integer> {
    int calls = 0;

    return suite;
  }

  Set<String> friends;
  Set<String> enemies;

  @Override
  public void setUp() {
    friends = Sets.newHashSet("Tom", "Joe", "Dave");
    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();

 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface Supplier<T extends @Nullable Object>
{
  /**