## Nested Models { #nested-models }

Each attribute of a Pydantic model has a type.

But that type can itself be another Pydantic model.

So, you can declare deeply nested JSON "objects" with specific attribute names, types and validations.

All that, arbitrarily nested.

### Define a submodel { #define-a-submodel }

For example, we can define an `Image` model:

 */
package okhttp3

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns.Companion.SYSTEM

/**
 * A domain name service that resolves IP addresses for host names. Most applications will use the
 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,

      "x01234567890123456789012345678901234567890123456789012345678901x",
      "x01234567890123456789012345678901234567890123456789012345678901†",
      // OkHttp rejects domain names longer than 253 code points, the web platform tests don't.

            Trans2FindFirst2Response resp = inv.getArgument(1);
            int call = nextCall[0]++;
            String[] names = batches.get(call + 1);
            FE[] res = java.util.Arrays.stream(names).map(FE::new).toArray(FE[]::new);
            setField(resp, jcifs.internal.smb1.trans.SmbComTransactionResponse.class, "results", res);
            if (call == 0) {

	// This only checks if the action (kms:ListKeys) is allowed, it does not check
	// each key name against the policy's Resources. We check that below, once
	// we have the list of key names from the KMS.
	objectAPI, _ := validateAdminReq(ctx, w, r, policy.KMSListKeysAction)
	if objectAPI == nil {
		return
	}

	if GlobalKMS == nil {

    int FLAGS_LOCK_AND_READ_WRITE_AND_UNLOCK = 0x01;
    /** Receive buffer posted flag */
    int FLAGS_RECEIVE_BUFFER_POSTED = 0x02;
    /** Path names are caseless flag */
    int FLAGS_PATH_NAMES_CASELESS = 0x08;
    /** Path names canonicalized flag */
    int FLAGS_PATH_NAMES_CANONICALIZED = 0x10;
    /** Oplock requested or granted flag */
    int FLAGS_OPLOCK_REQUESTED_OR_GRANTED = 0x20;

  // TODO(lukes): provide overloads that take constant strings? Function<Runnable, String>s to
  // calculate names?

  /**
   * Creates an {@link Executor} that renames the {@link Thread threads} that its tasks run in.
   *
   * <p>The names are retrieved from the {@code nameSupplier} on the thread that is being renamed

  /* The names of the expected method that tests null checks. */
  private static final ImmutableList<String> NULL_TEST_METHOD_NAMES =
      ImmutableList.of(
          "testNulls", "testNull",
          "testNullPointers", "testNullPointer",
          "testNullPointerExceptions", "testNullPointerException");

  /* The names of the expected method that tests serializable. */

            }

            assertEquals(160, totalSize); // 16+24+32+40+48
        }

        @Test
        @DisplayName("Should handle special SMB2 context names")
        void testSMB2ContextNames() {
            // Common SMB2 create context names
            String[] contextNames = { "DHnQ", // Durable handle request
                    "DHnC", // Durable handle reconnect
                    "AlSi", // Allocation size

     * we generate them in a testRoot which is contained in this directory.
     */
    private DirectoryProperty testRoot

    @Internal
    Set<String> names = new HashSet<>()

    @Inject
    RestTestsFromSnippetsTask(ObjectFactory objectFactory) {
        testRoot = objectFactory.directoryProperty()
        TestBuilder builder = new TestBuilder()