/** Flag in the opcode which indicates a control frame. */
  internal const val OPCODE_FLAG_CONTROL = 8

  /**
   * Byte 1 flag for whether the payload data is masked.
   *
   * If this flag is set, the next four
   * bytes represent the mask key. These bytes appear after any additional bytes specified by [B1_MASK_LENGTH].
   */
  internal const val B1_FLAG_MASK = 128

  /**
   * Byte 1 mask for the payload length.
   *

Check the in-code annotation tips above to see more specific details.

## Learn More { #learn-more }

You can also combine `dataclasses` with other Pydantic models, inherit from them, include them in your own models, etc.

To learn more, check the <a href="https://docs.pydantic.dev/latest/concepts/dataclasses/" class="external-link" target="_blank">Pydantic docs about dataclasses</a>.

## Version { #version }

# Advanced Middleware { #advanced-middleware }

In the main tutorial you read how to add [Custom Middleware](../tutorial/middleware.md){.internal-link target=_blank} to your application.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares { #adding-asgi-middlewares }

//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

              @Override
              protected void finalize() {
                finalizerRan.countDown();
              }
            });

    // Don't copy this into your own test!
    // Use e.g. awaitClear or await(CountDownLatch) instead.
    GcFinalization.awaitFullGc();

    // Attempt to help with some flakiness that we've seen: b/387521512.
    GcFinalization.awaitFullGc();

 * the behavior of {@link #putAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code