```

////

#### Using `Union` or `Optional`

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

* 🚨 Avoid using `Optional[SomeType]`
* Instead ✨ **use `Union[SomeType, None]`** ✨.

//
// An object storage system can implement one, multiple, or all functions.
//
//   - Optional (mandatory if <IAMSTS> is true): Set Endpoints for IAM and STS processing.
//
//   - Optional: Set server preferences for Backup & Replication parallel sessions, batch size of deletes, and block sizes (before
//     compression). This is an optional area; by default, there should be no <SystemRecommendations> section in the

     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    Optional<Boolean> force();

    /**
     * Should imply "yes" to all questions.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    Optional<Boolean> yes();

    /**

  public final Optional<@NonNull E> first() {
    Iterator<E> iterator = getDelegate().iterator();
    return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.absent();
  }

  /**
   * Returns an {@link Optional} containing the last element in this fluent iterable. If the
   * iterable is empty, {@code Optional.absent()} is returned. If the underlying {@code iterable} is

		config.HelpKV{
			Key:         target.WebhookAuthToken,
			Description: "opaque string or JWT authorization token",
			Optional:    true,
			Type:        "string",
			Sensitive:   true,
			Secret:      true,
		},
		config.HelpKV{
			Key:         config.Comment,
			Description: config.DefaultComment,
			Optional:    true,
			Type:        "sentence",
		},
		config.HelpKV{
			Key:         target.WebhookClientCert,

    return f"foo bar {query}"


@app.get("/query/optional")
def get_query_optional(query=None):
    if query is None:
        return "foo bar"
    return f"foo bar {query}"


@app.get("/query/int")
def get_query_type(query: int):
    return f"foo bar {query}"


@app.get("/query/int/optional")
def get_query_type_optional(query: Optional[int] = None):
    if query is None:
        return "foo bar"

    assertEquals(
        com.google.common.base.Optional.absent(),
        generator.generateFresh(new TypeToken<com.google.common.base.Optional<String>>() {}));
    assertEquals(
        com.google.common.base.Optional.of("2"),
        generator.generateFresh(new TypeToken<com.google.common.base.Optional<String>>() {}));
    // Test that the first generated instance for different cgcb.Optional<T> is always absent().

     *
     * @param dir the directory to locate the pom for, never {@code null}
     * @return a {@code Source} pointing to the located pom or an empty {@code Optional} if none was found by this parser
     */
    @Nonnull
    Optional<Source> locate(@Nonnull Path dir);

    /**
     * Parse the model obtained previously by a previous call to {@link #locate(Path)}.
     *

        @Override
        public Iterator<Lifecycle> iterator() {
            return Collections.emptyIterator();
        }

        @Override
        public Optional<Lifecycle> lookup(String id) {
            return Optional.empty();
        }

        @Override
        public List<String> computePhases(Lifecycle lifecycle) {
            return List.of();
        }
    };

from typing import List, Optional

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

app = FastAPI()


class Item(BaseModel):
    name: str
    price: Optional[float] = None
    owner_ids: Optional[List[int]] = None


@app.get("/items/valid", response_model=Item)
def get_valid():
    return {"name": "valid", "price": 1.0}


@app.get("/items/coerce", response_model=Item)