Je declareert de "vorm" van de data als klassen met attributen.

Elk attribuut heeft een type.

Vervolgens maak je een instantie van die klasse met een aantal waarden en het valideert de waarden, converteert ze naar het juiste type (als dat het geval is) en geeft je een object met alle data terug.

Daarnaast krijg je volledige editorondersteuning met dat resulterende object.

Een voorbeeld uit de officiële Pydantic-documentatie:

@Deprecated(since = "4.0.0")
public interface ToolchainManagerPrivate {

    /**
     * Retrieves every toolchains of given type available in user settings.
     *
     * @param type the type, must not be {@code null}
     * @param context the Maven session, must not be {@code null}
     * @since 3.0 (addition of the <code>MavenSession</code> parameter)
     */

     */
    public static void registerDriver(final Class<Driver> driverClass) {
        assertArgumentNotNull("driverClass", driverClass);
        registerDriver(ClassUtil.newInstance(driverClass));
    }

    /**
     * Registers a JDBC driver.
     *
     * @param driver
     *            The JDBC driver to register. Must not be {@literal null}.
     */

     * <code>maven-toolchains-plugin</code> contains the configuration to select the appropriate
     * toolchain and is executed at the beginning of the build.
     *
     * @param type the type, must not be {@code null}
     * @param context the Maven session, must not be {@code null}
     * @return the toolchain selected by <code>maven-toolchains-plugin</code>
     */
    Toolchain getToolchainFromBuildContext(String type, MavenSession context);

        NtlmMessage.writeSecurityBuffer(dest, 0, 8, payload);
        assertEquals(3, NtlmMessage.readUShort(dest, 0), "Length field must be 3");
        assertEquals(3, NtlmMessage.readUShort(dest, 2), "Length field must be 3 again");
        assertEquals(8, NtlmMessage.readULong(dest, 4), "Offset must point to payload start");
        byte[] actualPayload = new byte[payload.length];

    /**
     * Do not instantiate.
     */
    protected ModifierUtil() {
    }

    /**
     * Checks if the specified method is public.
     *
     * @param method
     *            the method to check. Must not be null.
     * @return true if public, false otherwise
     */
    public static boolean isPublic(final Method method) {
        assertArgumentNotNull("method", method);

   *   subjectPublicKeyInfo SubjectPublicKeyInfo,
   *   issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL, -- If present, version MUST be v2 or v3
   *   subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL, -- If present, version MUST be v2 or v3
   *   extensions      [3]  EXPLICIT Extensions OPTIONAL -- If present, version MUST be v3
   * }
   * ```
   */
  internal val tbsCertificate: BasicDerAdapter<TbsCertificate> =
    Adapters.sequence(

 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
@Provider
public interface SessionData {

    /**
     * Associates the specified session data with the given key.
     *
     * @param key the key under which to store the session data, must not be {@code null}

          graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
    }

    /**
     * Adds {@code node} if it is not already present.
     *
     * <p><b>Nodes must be unique</b>, just as {@code Map} keys must be. They must also be non-null.
     *
     * @return this {@code Builder} object
     */
    @CanIgnoreReturnValue
    public ImmutableValueGraph.Builder<N, V> addNode(N node) {

      assertTrue(item + " must not be Object#equals to null", !item.equals(null));
      assertTrue(
          item + " must not be Object#equals to an arbitrary object of another class",
          !item.equals(NotAnInstance.EQUAL_TO_NOTHING));
      assertTrue(item + " must be Object#equals to itself", item.equals(item));
      assertEquals(
          "the Object#hashCode of " + item + " must be consistent",
          item.hashCode(),