If you declare the return type, FastAPI will use it to **validate** the data, **document** it in OpenAPI, **filter** it, and **serialize** it using Pydantic.

/// tip

As Pydantic will serialize it in the **Rust** side, you will get much higher **performance** than if you don't declare a return type.

///

     */
    private final Smb2LeaseKey leaseKey;

    /**
     * Flag indicating whether this handle is currently being reconnected
     */
    private volatile boolean reconnecting;

    // Not serialized - will be null after deserialization
    private transient Object file; // Reference to SmbFile (avoid circular dependencies)

    /**
     * Create new handle information
     * @param path the file path

                    not include that field, the JSON sent to the client would not have
                    that `password`.
                * Validation: whatever you return will be serialized with the
                    `response_model`, converting any data as necessary to generate the
                    corresponding JSON. But if the data in the object returned is not

  client_job->mutable_tasks()->insert(
      {0, absl::StrCat("localhost:", client_port)});
  server_def.set_job_name("localhost");
  auto serialized = server_def.SerializeAsString();
  TFE_ContextSetServerDef(ctx, 0, serialized.data(), serialized.size(), status);
  EXPECT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);

  EXPECT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);

	"github.com/minio/minio/internal/s3select/sql"
)

// RawJSON is a byte-slice that contains valid JSON
type RawJSON []byte

// MarshalJSON instance for []byte that assumes that byte-slice is
// already serialized JSON
func (b RawJSON) MarshalJSON() ([]byte, error) {
	return b, nil
}

// Record - is JSON record.
type Record struct {
	// Used in Set(), Marshal*()
	KVS jstream.KVS

        AtomicDouble a = new AtomicDouble(x);
        double z = a.addAndGet(y);
        assertBitEquals(x + y, z);
        assertBitEquals(x + y, a.get());
      }
    }
  }

  /** a deserialized serialized atomic holds same value */
  public void testSerialization() throws Exception {
    AtomicDouble a = new AtomicDouble();
    AtomicDouble b = serialClone(a);
    assertThat(b).isNotSameInstanceAs(a);

    return new SerializedForm<>(delegate());
  }

    private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  /** Serialized form of the map, to avoid serializing the constraint. */
  private static final class SerializedForm<B extends @Nullable Object> implements Serializable {
    private final Map<Class<? extends @NonNull B>, B> backingMap;

    `com.google.guava:failureaccess:1.0.3`. It also has
    [some annotation-only dependencies][guava-deps], which we discuss in more
    detail at that link.

4.  Serialized forms of ALL objects are subject to change unless noted
    otherwise. Do not persist these and assume they can be read by a future
    version of the library.

    return new SerializedForm<>(delegate());
  }

    private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  /** Serialized form of the map, to avoid serializing the constraint. */
  private static final class SerializedForm<B extends @Nullable Object> implements Serializable {
    private final Map<Class<? extends @NonNull B>, B> backingMap;

			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	o = bts
	return
}

// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
func (z *ServerSystemConfig) Msgsize() (s int) {
	s = 1 + 11 + msgp.IntSize + 9 + msgp.ArrayHeaderSize
	for za0001 := range z.CmdLines {
		s += msgp.StringPrefixSize + len(z.CmdLines[za0001])
	}