The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.9+) is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

But adding the type annotations will allow your editor to give you better support and detect errors.

///

## Without Pydantic { #without-pydantic }

import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashSet is an implementation of a Set, which a predictable iteration order that
 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)

import java.util.Spliterators;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashSet is an implementation of a Set, which a predictable iteration order that
 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)

   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(String string, int radix) {
    return fromLongBits(UnsignedLongs.parseUnsignedLong(string, radix));
  }

  /**
   * Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
   * returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong plus(UnsignedLong val) {

                log.debug("  Excluded {}", id);
            } else {
                File file = artifact.getFile();
                log.debug("  Included {} located at {}", id, file);
                realm.addURL(file.toURI().toURL());
            }
        }
        return CoreExtensionEntry.discoverFrom(
                realm,
                Collections.singleton(artifacts.get(0).getFile()),

* how many of our REST services do not map directory to a method in the application interface?

- an example of adding js

  
  Portworx CSI driver is required to enable migration.
  This PR adds support of the `CSIMigrationPortworx` feature gate, which can be enabled by:
  
  1. Adding the feature flag to the kube-controller-manager `--feature-gates=CSIMigrationPortworx=true` 
  2. Adding the feature flag to the kubelet config:
  
  featureGates:

pkg log/slog, method (*MultiHandler) WithGroup(string) Handler #65954
pkg log/slog, type MultiHandler struct #65954
pkg net, method (*Dialer) DialIP(context.Context, string, netip.Addr, netip.Addr) (*IPConn, error) #49097
pkg net, method (*Dialer) DialTCP(context.Context, string, netip.AddrPort, netip.AddrPort) (*TCPConn, error) #49097

        // Then
        assertNotNull(exception.getContext());
        assertTrue(exception.getContext().isEmpty());

        // Adding null context should be safe
        exception.withContext(null);
        assertTrue(exception.getContext().isEmpty());
    }

    @Test
    @DisplayName("Should be serializable")

If there are compelling use cases for early closing in dependencies with `yield`, I would consider adding a new way to opt in to early closing.

### Dependencies with `yield` and `except`, Technical Details { #dependencies-with-yield-and-except-technical-details }