],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }
  ]
}
```

これは、パスパラメータ `item_id` が `int` ではない値 `"foo"` だからです。

[http://127.0.0.1:8000/items/4.2](http://127.0.0.1:8000/items/4.2) で見られるように、`int` のかわりに `float` が与えられた場合にも同様なエラーが表示されます。

/// check | 確認

したがって、同じPythonの型宣言を使用することで、**FastAPI**はデータのバリデーションを行います。

表示されたエラーには、バリデーションが通らなかった箇所が明確に示されていることに注意してください。

public interface OneSizeTestContainerGenerator<T, E extends @Nullable Object>
    extends TestSubjectGenerator<T>, TestContainerGenerator<T, E> {
  TestContainerGenerator<T, E> getInnerGenerator();

  Collection<E> getSampleElements(int howMany);

  CollectionSize getCollectionSize();

      return false;
    }

    ElementOrder<?> other = (ElementOrder<?>) obj;
    return (type == other.type) && Objects.equals(comparator, other.comparator);
  }

  @Override
  public int hashCode() {
    return Objects.hash(type, comparator);
  }

  @Override
  public String toString() {
    ToStringHelper helper = MoreObjects.toStringHelper(this).add("type", type);
    if (comparator != null) {

	CipherSuites     []uint16
	CurvePreferences []tls.CurveID

	// HTTP2
	EnableHTTP2 bool

	// TCP Options
	TCPOptions TCPOptions
}

func (s ConnSettings) getDefaultTransport(maxIdleConnsPerHost int) *http.Transport {
	if maxIdleConnsPerHost <= 0 {
		maxIdleConnsPerHost = 1024
	}

	dialContext := s.DialContext
	if dialContext == nil {

          host: InetAddress,
          port: Int,
        ): Socket? = null

        override fun createSocket(
          address: InetAddress,
          port: Int,
          localAddress: InetAddress,
          localPort: Int,
        ): Socket? = null

        override fun createSocket(
          host: String,
          port: Int,
        ): Socket? = null

    protected static final String CRAWLER_CLIENTS = "crawlerClients";

    /** HTTP status code for Not Found */
    private static final int HTTP_STATUS_NOT_FOUND = 404;

    /** HTTP status code for OK */
    private static final int HTTP_STATUS_OK = 200;

    /**
     * Cache for client rules mapping client names to their corresponding URL patterns.

     * @param server the server name to connect to
     * @param access the desired access rights
     * @param policyHandle the policy handle to be populated
     */
    public MsrpcSamrConnect4(final String server, final int access, final SamrPolicyHandle policyHandle) {
        super(server, 2, access, policyHandle);
        this.ptype = 0;
        this.flags = DCERPC_FIRST_FRAG | DCERPC_LAST_FRAG;
    }

 * javadoc for details.
 */
@GwtCompatible
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

  public static CommonPattern compile(String pattern) {

        } else {
            keyStr = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, keyStr);
        }
        return keyStr;
    }

    @Override
    public int size() {
        return parent.size();
    }

    @Override
    public boolean isEmpty() {
        return parent.isEmpty();
    }

    @Override
    public boolean containsKey(final Object key) {

        .hasMessageThat()
        .isEqualTo("Timed out waiting for Foo [STARTING] to reach the RUNNING state.");
  }

  private static class TestService extends AbstractIdleService {
    int startUpCalled = 0;
    int shutDownCalled = 0;
    final List<State> transitionStates = new ArrayList<>();

    @Override
    protected void startUp() throws Exception {
      assertEquals(0, startUpCalled);