*/
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  private final E element;

  SingletonImmutableSet(E element) {
    this.element = checkNotNull(element);
  }

  @Override
  public int size() {
    return 1;
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.singletonIterator(element);
  }

  @Override
  public boolean contains(@Nullable Object object) {

Ahora intenta enviar un ítem inválido como:

```JSON
{
  "title": "towel",
  "size": "XL"
}
```

Recibirás un response que te dirá que los datos son inválidos conteniendo el body recibido:

```JSON hl_lines="12-15"
{
  "detail": [
    {
      "loc": [
        "body",
        "size"
      ],
      "msg": "value is not a valid integer",
      "type": "type_error.integer"
    }

Tente enviar um item inválido como este:

```JSON
{
  "title": "towel",
  "size": "XL"
}
```

Você receberá uma *response* informando-o de que a data é inválida, e contendo o *body* recebido:

```JSON hl_lines="12-15"
{
  "detail": [
    {
      "loc": [
        "body",
        "size"
      ],
      "msg": "value is not a valid integer",
      "type": "type_error.integer"

            }

            final StringBuilder buf = new StringBuilder(255);
            buf.append("\"record_count\":").append(docIdList.size());
            buf.append(", \"data\":[");
            if (!docIdList.isEmpty()) {
                for (int i = 0; i < docIdList.size(); i++) {
                    if (i > 0) {
                        buf.append(',');
                    }

        this.allow = buf[bi] == (byte) 0x00;
        bi++;
        this.flags = buf[bi++] & 0xFF;
        final int size = SMBUtil.readInt2(buf, bi);
        bi += 2;
        this.access = SMBUtil.readInt4(buf, bi);
        bi += 4;
        this.sid = new SID(buf, bi);
        return size;
    }

    void appendCol(final StringBuffer sb, final String str, final int width) {
        sb.append(str);

        assertEquals("TEST.REALM", encData.getUserRealm());
        assertEquals("testuser", encData.getUserPrincipalName());
        assertNotNull(encData.getUserAddresses());
        assertEquals(1, encData.getUserAddresses().size());
        assertEquals(InetAddress.getByName("127.0.0.1"), encData.getUserAddresses().get(0));
        assertNotNull(encData.getUserAuthorizations());

        }

        if (_specification != null) {
            builder.setFetchSource(_specification.columnList.toArray(new String[_specification.columnList.size()]), null);
        }

        return builder;
    }

    // ===================================================================================

    interfaceClasses.add(Serializable.class);
    Object dummy =
        Proxy.newProxyInstance(
            interfaceClasses.iterator().next().getClassLoader(),
            interfaceClasses.toArray(new Class<?>[interfaceClasses.size()]),
            new DummyHandler(interfaceType));
    @SuppressWarnings("unchecked") // interfaceType is T
    T result = (T) dummy;
    return result;
  }

ECL0012=argument[{0}] is null or empty collection.
ECL0013=argument[{0}] is null or empty map.
ECL0014=argument[{0}] which is null the index of array is negative integer.
ECL0015=argument[{0}] which is null the index of array exceed the size of array[{1}].
ECL0016=key[{0}] is not included in this BeanMap : {1}.
ECL0017=Exception occurred, because {0}
ECL0041={0}''s creation failure, because {1}
ECL0040=IOException occurred, because {0}

 * sample of code points to detect unicode control characters commonly used in binary file
 * signatures.
 */
fun Buffer.isProbablyUtf8(): Boolean {
  try {
    val prefix = Buffer()
    val byteCount = size.coerceAtMost(64)
    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()