}

  public void testToString() {
    assertEquals("foo", entry("foo", 1).toString());
    assertEquals("bar x 2", entry("bar", 2).toString());
  }

  public void testToStringNull() {
    assertEquals("null", entry(NE, 1).toString());
    assertEquals("null x 2", entry(NE, 2).toString());
  }

  public void testEquals() {
    assertEquals(control("foo", 1), entry("foo", 1));

  }

  public void testToString() {
    assertEquals("foo", entry("foo", 1).toString());
    assertEquals("bar x 2", entry("bar", 2).toString());
  }

  public void testToStringNull() {
    assertEquals("null", entry(NE, 1).toString());
    assertEquals("null x 2", entry(NE, 2).toString());
  }

  public void testEquals() {
    assertEquals(control("foo", 1), entry("foo", 1));

      K key, V value) {
    return singletonMap(key, value).entrySet().iterator().next();
  }

  public void testToString() {
    assertEquals("foo=1", entry("foo", 1).toString());
  }

  public void testToStringNull() {
    assertEquals("null=1", entry(NK, 1).toString());
    assertEquals("foo=null", entry("foo", NV).toString());
    assertEquals("null=null", entry(NK, NV).toString());
  }

  public void testEquals() {