*
   * @see <a href=
   *     "http://code.google.com/webtoolkit/doc/latest/DevGuideServerCommunication.html#DevGuideSerializableTypes">
   *     Documentation about GWT serialization</a>
   */
  boolean serializable() default false;

  /**
   * When {@code true}, the annotated type is emulated in GWT. The emulated source (also known as
   * super-source) is different from the implementation used by the JVM.
   *
   * @see <a href=

     * @return an URL handler using this context
     */
    URLStreamHandler getUrlHandler ();


    /**
     * @return whether default credentials are available
     */
    boolean hasDefaultCredentials ();


    /**
     * @return a child context using the configured default credentials
     */
    CIFSContext withDefaultCredentials ();


    /**

    public static RepositoryPolicy toRepositoryPolicy(org.apache.maven.model.RepositoryPolicy policy) {
        boolean enabled = true;
        String checksums = toRepositoryChecksumPolicy(RepositoryPolicy.CHECKSUM_POLICY_WARN); // the default
        String updates = RepositoryPolicy.UPDATE_POLICY_DAILY;

        if (policy != null) {
            enabled = policy.isEnabled();
            if (policy.getUpdatePolicy() != null) {

		if _, err := uuid.Parse(vid); err != nil {
			return opts, InvalidVersionID{
				Bucket:    bucket,
				Object:    object,
				VersionID: vid,
			}
		}
	}

	// default case of passing encryption headers to backend
	opts, err = getDefaultOpts(r.Header, false, nil)
	if err != nil {
		return opts, err
	}
	opts.PartNumber = partNumber
	opts.VersionID = vid

```

由于我们必须用 `Query(default=None)` 替换默认值 `None`，`Query` 的第一个参数同样也是用于定义默认值。

所以：

```Python
q: Union[str, None] = Query(default=None)
```

...使得参数可选，等同于：

```Python
q: str = None
```

但是 `Query` 显式地将其声明为查询参数。

然后，我们可以将更多的参数传递给 `Query`。在本例中，适用于字符串的 `max_length` 参数：

```Python
q: Union[str, None] = Query(default=None, max_length=50)
```

     * If not set, System.in will be used by default.
     *
     * @return the input stream, or null if not set
     */
    @Nullable
    InputStream in();

    /**
     * Returns the output stream to be used for the Maven execution.
     * If not set, System.out will be used by default.
     *
     * @return the output stream, or null if not set
     */
    @Nullable

		}
	default:
		m.disconnect("handler blocked", true)
	}
}

func (m *muxServer) unblockSend(seq uint32) {
	if !m.checkSeq(seq) {
		return
	}
	m.recvMu.Lock()
	defer m.recvMu.Unlock()
	if m.outBlock == nil {
		// Closed
		return
	}
	select {
	case m.outBlock <- struct{}{}:
	default:
		gridLogIf(m.ctx, errors.New("output unblocked overflow"))

     *             installation has failed.
     * @throws IllegalArgumentException in case of parameter {@code session} is {@code null} or
     *          {@code artifact} is {@code null}.
     */
    default void install(Session session, ProducedArtifact artifact) {
        install(session, Collections.singletonList(artifact));
    }

    /**
     * @param session the repository session

from typing import Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Union[str, None] = Query(
        default=None,
        title="Query string",
        description="Query string for the items to search in the database that have a good match",
        min_length=3,
    ),
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:

# Properties used to build to the RPM package
#

# Environment file
packaging.env.file=/etc/sysconfig/fess

# Default configuration directory and file to use in bin/plugin script

# Simple marker to check that properties are correctly overridden
packaging.type=rpm

# Custom header for package scripts
packaging.scripts.header=