return e1().getValue();
  }

  protected final K k2() {
    return e2().getKey();
  }

  protected final V v2() {
    return e2().getValue();
  }

  protected final K k3() {
    return e3().getKey();
  }

  protected final V v3() {
    return e3().getValue();
  }

  protected final K k4() {
    return e4().getKey();
  }

  protected final V v4() {

  private Entry<K, V> presentKeyNullValueEntry;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    nullKeyEntry = entry(null, v3());
    nullValueEntry = entry(k3(), null);
    nullKeyValueEntry = entry(null, null);
    presentKeyNullValueEntry = entry(k0(), null);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)

	{"[]", "register list: bad low register in `[]`"},
	{"[f-x]", "register list: bad low register in `[f`"},
	{"[r10-r13]", "register list: bad low register in `[r10`"},
	{"[k3-k6]", "register list: bad low register in `[k3`"},
	{"[X0]", "register list: expected '-' after `[X0`, found ']'"},
	{"[X0-]", "register list: bad high register in `[X0-]`"},
	{"[X0-x]", "register list: bad high register in `[X0-x`"},