* {@link Predicate} that it considers <i>interchangeable</i> with this one. "Interchangeable"
   * <i>typically</i> means that {@code this.apply(t) == that.apply(t)} for all {@code t} of type
   * {@code T}). Note that a {@code false} result from this method does not imply that the
   * predicates are known <i>not</i> to be interchangeable.
   */
  @Override
  boolean equals(@CheckForNull Object object);

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

So, you will receive a clean error, with an HTTP status code of `418` and a JSON content of:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | "Technical Details"

You could also use `from starlette.requests import Request` and `from starlette.responses import JSONResponse`.

但该异常将会被 `unicorn_exception_handler` 处理。

接收到的错误信息清晰明了，HTTP 状态码为 `418`，JSON 内容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}

```

/// note | "技术细节"

`from starlette.requests import Request` 和 `from starlette.responses import JSONResponse` 也可以用于导入 `Request` 和 `JSONResponse`。

  }

  /**
   * Returns {@code true} if {@code object} is a {@link HashCode} instance with the identical byte
   * representation to this hash code.
   *
   * <p><b>Security note:</b> this method uses a constant-time (not short-circuiting) implementation
   * to protect against <a href="http://en.wikipedia.org/wiki/Timing_attack">timing attacks</a>.
   */
  @Override

import java.util.concurrent.atomic.AtomicBoolean;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Utilities necessary for working with libraries that supply plain {@link Future} instances. Note
 * that, whenever possible, it is strongly preferred to modify those libraries to return {@code
 * ListenableFuture} directly.
 *
 * <p>For interoperability between {@code ListenableFuture} and <b>{@code CompletableFuture}</b>,

   * Returns an {@link ImmutableValueGraph.Builder} with the properties of this {@link
   * ValueGraphBuilder}.
   *
   * <p>The returned builder can be used for populating an {@link ImmutableValueGraph}.
   *
   * <p>Note that the returned builder will always have {@link #incidentEdgeOrder} set to {@link
   * ElementOrder#stable()}, regardless of the value that was set in this builder.
   *
   * @since 28.0
   */

      process(readBuffer);
    }

    // Finally stick the remainder back in our usual buffer
    buffer.put(readBuffer);
    return this;
  }

  /*
   * Note: hashString(CharSequence, Charset) is intentionally not overridden.
   *
   * While intuitively, using CharsetEncoder to encode the CharSequence directly to the buffer (or

 * for information on the behaviour of the algorithm.
 *
 * <p>On Intel Core2 2.66, on 1000 bytes, fingerprint2011 takes 0.9 microseconds compared to
 * fingerprint at 4.0 microseconds and md5 at 4.5 microseconds.
 *
 * <p>Note to maintainers: This implementation relies on signed arithmetic being bit-wise equivalent
 * to unsigned arithmetic in all cases except:
 *
 * <ul>
 *   <li>comparisons (signed values can be negative)

```Python hl_lines="9"
{!> ../../docs_src/query_params/tutorial002.py!}
```

////

本例中，查询参数 `q` 是可选的，默认值为 `None`。

/// check | "检查"

注意，**FastAPI** 可以识别出 `item_id` 是路径参数，`q` 不是路径参数，而是查询参数。

///

/// note | "笔记"

因为默认值为 `= None`，FastAPI 把 `q` 识别为可选参数。

FastAPI 不使用 `Optional[str]` 中的 `Optional`（只使用 `str`），但 `Optional[str]` 可以帮助编辑器发现代码中的错误。

///

## 查询参数类型转换

参数还可以声明为 `bool` 类型，FastAPI 会自动转换参数类型：