func (b *Batch[K, T]) Len() int {
	b.Lock()
	defer b.Unlock()

	return len(b.keys)
}

// IsFull checks if the batch is full or not
func (b *Batch[K, T]) IsFull() bool {
	b.Lock()
	defer b.Unlock()

	return b.isFull()
}

func (b *Batch[K, T]) isFull() bool {
	return len(b.items) >= int(b.limit)
}

// NewBatch creates a new batch

    assertThat(stringPrep("\uf8ff")).isNull()
    assertThat(stringPrep("\udbff\udffd")).isNull() // Note that this is one code point.
  }

  @Test fun prohibitionNonCharacter() {
    assertThat(stringPrep("\ufdd0")).isNull()
    assertThat(stringPrep("\ufffe")).isNull()
    assertThat(stringPrep("\udbff\udffe")).isNull()
  }

  /**
   * Because our API always transcodes through UTF-8, and that transcoding replaces unpaired

        .url("https://square.com")
        .build()
    assertThat(request.tag<Any>()).isNull()
    assertThat(request.tag(Any::class)).isNull()
    assertThat(request.tag(String::class)).isNull()

    // Alternate access APIs also work.
    assertThat(request.tag<String>()).isNull()
    assertThat(request.tag(String::class)).isNull()
  }

  @Test
  fun defaultTag() {
    val tag = "1234"
    val request =

    assertThat(publicSuffixDatabase.getEffectiveTldPlusOne("aaa")).isNull()
    assertThat(publicSuffixDatabase.getEffectiveTldPlusOne("ggg")).isNull()
    assertThat(publicSuffixDatabase.getEffectiveTldPlusOne("ccc")).isNull()
    assertThat(publicSuffixDatabase.getEffectiveTldPlusOne("eee")).isNull()
  }

  @Test fun exceptionRule() {
    val exception =
      Buffer()

    assertThat(parse(url, "a\u0000b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0000d")).isNull()
    assertThat(parse(url, "a\u0001b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0001d")).isNull()
    assertThat(parse(url, "a\u0009b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0009d")).isNull()
    assertThat(parse(url, "a\u001fb=cd")).isNull()
    assertThat(parse(url, "ab=c\u001fd")).isNull()

    taskFaker.runNextTask()

    // Don't allow edits under any circumstances.
    assertThat(cache.edit("a")).isNull()
    assertThat(cache.edit("c")).isNull()
    cache["a"]!!.use {
      assertThat(it.edit()).isNull()
    }
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)

    assertThat(graph.removeEdge(1, 2)).isEqualTo("valueA");
    assertThat(graph.removeEdge(1, 2)).isNull();
    assertThat(graph.removeEdge(2, 1)).isEqualTo("valueB");
    assertThat(graph.removeEdge(2, 1)).isNull();
    assertThat(graph.removeEdge(2, 3)).isEqualTo("valueC");
    assertThat(graph.removeEdge(2, 3)).isNull();
  }

  @Test
  public void removeEdge_undirected() {

    assertThat(graph.edgeValue(2, 1).orElse(DEFAULT)).isEqualTo(DEFAULT);
    assertThat(graph.edgeValueOrDefault(1, 2, null)).isNull();
    assertThat(graph.edgeValueOrDefault(2, 1, null)).isNull();
    assertThat(graph.edgeValue(1, 2).orElse(null)).isNull();
    assertThat(graph.edgeValue(2, 1).orElse(null)).isNull();

    graph.putEdgeValue(1, 2, "valueA");
    graph.putEdgeValue(2, 1, "valueB");

    assertThat("Thu, 01 Jan 1970 00:00:00".toHttpDateOrNull()).isNull()
    // Missing seconds treated as bad.
    assertThat("Thu, 01 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()
    // Extra spaces treated as bad.
    assertThat("Thu,  01 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()
    // Missing leading zero treated as bad.
    assertThat("Thu, 1 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()

    // RFC 850, obsoleted by RFC 1036 with any TZ.

  }

  /*
   * Tests for Predicates.isNull()
   */

  public void testIsNull_apply() {
    Predicate<@Nullable Integer> isNull = Predicates.isNull();
    assertTrue(isNull.apply(null));
    assertFalse(isNull.apply(1));
  }

  public void testIsNull_equality() {
    new EqualsTester()
        .addEqualityGroup(Predicates.isNull(), Predicates.isNull())
        .addEqualityGroup(Predicates.notNull())