canUseHeaderValue = false
        } else {
          headerValue = value
        }
      }
      name.equals("Pragma", ignoreCase = true) -> {
        // Might specify additional cache-control params. We invalidate just in case.
        canUseHeaderValue = false
      }
      else -> {
        continue@loop
      }
    }

    var pos = 0

For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases { #use-cases }

Some use cases include:

#!/usr/bin/env bash
#
# Copyright 2022 The TensorFlow Authors. All Rights Reserved.
#
# Licensed 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
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,

* `description`: A long description that can contain Markdown text.
* `value`: This is the actual example shown, e.g. a `dict`.
* `externalValue`: alternative to `value`, a URL pointing to the example. Although this might not be supported by as many tools as `value`.

You can use it like this:

{* ../../docs_src/schema_extra_example/tutorial005_an_py310.py hl[23:49] *}

        // that. If any of the BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS ended in "'GMT'" we'd have
        // to also check that position.getIndex() == value.length() otherwise parsing might have
        // terminated early, ignoring things like "+01:00". Leaving this as != 0 means that any
        // trailing junk is ignored.
        return result
      }
    }
  }
  return null
}

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests that all package-private {@code writeReplace} methods are overridden in any existing
 * subclasses. Without such overrides, optimizers might put a {@code writeReplace}-containing class
 * and its subclass in different packages, causing the serialization system to fail to invoke {@code

     * do that with a plain NonTerminalImmutableMapEntry, but we do it with the BiMap-specific
     * subclass below. That's because the Entry might be non-terminal in the key bucket but terminal
     * in the value bucket (or vice versa).
     */
    private final transient @Nullable ImmutableMapEntry<K, V> nextInKeyBucket;

    NonTerminalImmutableMapEntry(

     *
     * @see jcifs.internal.SmbBasicFileInfo#getSize()
     */
    @Override
    public long getSize() {
        return getDataSize();
    }

    /**
     * Gets the granted access rights.
     *
     * @return the grantedAccess
     */
    public final int getGrantedAccess() {
        return this.grantedAccess;
    }

    /**
     * Gets the file attributes.
     *

# Copyright 2023 The TensorFlow Authors. All Rights Reserved.
#
# Licensed 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
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,

  }

  /**
   * Sets the minimum total size for the internal hash tables. For example, if the initial capacity
   * is {@code 60}, and the concurrency level is {@code 8}, then eight segments are created, each
   * having a hash table of size eight. Providing a large enough estimate at construction time
   * avoids the need for expensive resizing operations later, but setting this value unnecessarily
   * high wastes memory.
   *