* implementations.
   */
  SUPPORTS_SET;

  /**
   * A set containing none of the optional features of the {@link Iterator} or {@link ListIterator}
   * interfaces.
   */
  public static final Set<IteratorFeature> UNMODIFIABLE = emptySet();

  /**
   * A set containing all of the optional features of the {@link Iterator} and {@link ListIterator}
   * interfaces.
   */

- **路径**中声明了相同参数的参数，是路径参数
- 类型是（`int`、`float`、`str`、`bool` 等）**单类型**的参数，是**查询**参数
- 类型是 **Pydantic 模型**的参数，是**请求体**

/// note | "笔记"

因为默认值是 `None`， FastAPI 会把 `q` 当作可选参数。

FastAPI 不使用 `Optional[str]` 中的 `Optional`， 但 `Optional` 可以让编辑器提供更好的支持，并检测错误。

///

## 不使用 Pydantic

    }

    private static void trimValues(MavenProperties configProps) {
        configProps.replaceAll((k, v) -> v.trim());
    }

    private static String nextLocation(StringTokenizer st) {
        boolean optional = false;
        String retVal = null;

        if (st.countTokens() > 0) {
            String tokenList = "?\",";
            StringBuilder tokBuf = new StringBuilder(10);
            String tok;

        return delegate.getExecutionId();
    }

    @Override
    public String getGoal() {
        return delegate.getGoal();
    }

    @Override
    public Optional<XmlNode> getConfiguration() {
        return Optional.of(delegate.getConfiguration()).map(Xpp3Dom::getDom);
    }

    @Override
    public String toString() {
        return delegate.toString();
    }

    DependencyScope getScope();

    /**
     * Returns whether the dependency is optional or mandatory.
     * Contrarily to {@link DependencyCoordinates}, the obligation of a {@code Dependency} is always present.
     * The value is computed during the dependencies collection phase.
     *
     * @return {@code true} if the dependency is optional, or {@code false} if mandatory
     * @see DependencyCoordinates#getOptional()
     */

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.mylasta.direction.sponsor;

import java.util.TimeZone;

import org.dbflute.optional.OptionalObject;
import org.dbflute.optional.OptionalThing;
import org.dbflute.util.DfTypeUtil;
import org.lastaflute.web.ruts.process.ActionRuntime;
import org.lastaflute.web.servlet.request.RequestManager;

   */
  private int findSuffixOfType(Optional<PublicSuffixType> desiredType) {
    int partsSize = parts.size();

    for (int i = 0; i < partsSize; i++) {
      String ancestorName = DOT_JOINER.join(parts.subList(i, partsSize));

      if (i > 0
          && matchesType(
              desiredType, Optional.fromNullable(PublicSuffixPatterns.UNDER.get(ancestorName)))) {
        return i - 1;

def get_current_user(oauth_header: Optional[str] = Security(reusable_oauth2)):
    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.post("/login")
def login(form_data: OAuth2PasswordRequestFormStrict = Depends()):
    return form_data


@app.get("/users/me")
def read_users_me(current_user: Optional[User] = Depends(get_current_user)):

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api;

import java.util.List;
import java.util.Optional;
import java.util.function.Predicate;
import java.util.stream.Stream;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;

	Handler    HandlerID // ID of handler if invoking a remote handler.
	Op         Op        // Operation. Other fields change based on this value.
	Flags      Flags     // Optional flags.
	Payload    []byte    // Optional payload.
}

// Flags is a set of flags set on a message.
type Flags uint8

func (m message) String() string {
	var res []string
	if m.MuxID != 0 {