// v1 == 0.
        .optional(defaultValue = 0),
      Adapters.INTEGER_AS_BIG_INTEGER,
      algorithmIdentifier,
      name,
      validity,
      name,
      subjectPublicKeyInfo,
      Adapters.BIT_STRING.withTag(tag = 1L).optional(),
      Adapters.BIT_STRING.withTag(tag = 2L).optional(),
      extension.asSequenceOf().withExplicitBox(tag = 3).optional(defaultValue = listOf()),
      decompose = {

            @Nonnull
            @Override
            public Optional<Source> getInstallationToolchainsSource() {
                return Optional.ofNullable(installationToolchainsSource);
            }

            @Nonnull
            @Override
            public Optional<Source> getUserToolchainsSource() {
                return Optional.ofNullable(userToolchainsSource);
            }

            @Override

    /**
     * Performs a lookup for optional typed component.
     *
     * @param type The component type.
     * @return Optional carrying component or empty optional if no such component.
     * @param <T> The component type.
     * @throws LookupException if there is some provisioning related issue.
     */
    @Nonnull
    <T> Optional<T> lookupOptional(Class<T> type);

    /**

    }

    @Override
    public Optional<Path> rootDirectory() {
        return Optional.ofNullable(rootDirectory);
    }

    @Override
    public Optional<List<CoreExtensions>> coreExtensions() {
        return Optional.ofNullable(coreExtensions);
    }

    @Override
    public Optional<CIInfo> ciInfo() {
        return Optional.ofNullable(ciInfo);
    }

    scope: Optional string. Several scopes (each one a string) separated by spaces. E.g.
        "items:read items:write users:read profile openid"
    client_id: optional string. OAuth2 recommends sending the client_id and client_secret (if any)
        using HTTP Basic auth, as: client_id:client_secret
    client_secret: optional string. OAuth2 recommends sending the client_id and client_secret (if any)

@REM
@REM   JAVA_HOME           (Optional) Points to a Java installation.
@REM   MAVEN_BATCH_ECHO    (Optional) Set to 'on' to enable the echoing of the batch commands.
@REM   MAVEN_BATCH_PAUSE   (Optional) set to 'on' to wait for a key stroke before ending.
@REM   MAVEN_OPTS          (Optional) Java runtime options used when Maven is executed.
@REM   MAVEN_SKIP_RC       (Optional) Flag to disable loading of mavenrc files.

            return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    public Optional<Boolean> showVersion() {
        if (commandLine.hasOption(CLIManager.SHOW_VERSION)) {
            return Optional.of(Boolean.TRUE);
        }
        return Optional.empty();
    }

    @Override
    public Optional<Boolean> quiet() {

    public <T> T lookup(Class<T> type, String name) {
        return null;
    }

    @Override
    public <T> Optional<T> lookupOptional(Class<T> type) {
        return Optional.empty();
    }

    @Override
    public <T> Optional<T> lookupOptional(Class<T> type, String name) {
        return Optional.empty();
    }

    @Override
    public <T> List<T> lookupList(Class<T> type) {
        return List.of();
    }

   * Point ::= SEQUENCE {
   *   x [0] INTEGER OPTIONAL,
   *   y [1] INTEGER OPTIONAL
   * }
   * ```
   *
   * You may also specify a tag class like [DerHeader.TAG_CLASS_APPLICATION]. The default tag class
   * is [DerHeader.TAG_CLASS_CONTEXT_SPECIFIC].
   *
   * ```
   * Point ::= SEQUENCE {
   *   x [APPLICATION 0] INTEGER OPTIONAL,
   *   y [APPLICATION 1] INTEGER OPTIONAL
   * }
   * ```
   */
  fun withTag(

from typing import Optional

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class SubModel(BaseModel):
    a: Optional[str] = "foo"


class Model(BaseModel):
    x: Optional[int] = None
    sub: SubModel


class ModelSubclass(Model):
    y: int
    z: int = 0
    w: Optional[int] = None


class ModelDefaults(BaseModel):