* challenges, we prefer to use the same physical connection for all streams in the sequence. There
 * are potential performance and behavior consequences to this preference. To support this feature,
 * this class separates _allocations_ from _streams_. An allocation is created by a call, used for
 * one or more streams, and then released. An allocated connection won't be stolen by other calls
 * while a redirect or authorization challenge is being handled.
 *

  /**
   * Returns the inverse view of this bimap, which maps each of this bimap's values to its
   * associated key. The two bimaps are backed by the same data; any changes to one will appear in
   * the other.
   *
   * <p><b>Note:</b> There is no guaranteed correspondence between the iteration order of a bimap
   * and that of its inverse.
   *
   * @return the inverse view of this bimap
   */
  BiMap<V, K> inverse();

# Templates { #templates }

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies { #install-dependencies }

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * 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,

   *
   * @param formal The type whose type variables or itself is mapped to other type(s). It's almost
   *     always a bug if {@code formal} isn't a type variable and contains no type variable. Make
   *     sure you are passing the two parameters in the right order.
   * @param actual The type that the formal type variable(s) are mapped to. It can be or contain yet
   *     other type variables, in which case these type variables will be further resolved if

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * 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,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * 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,

   * the first duplicate.
   */

  // This entry point is for callers other than ImmutableMap.Builder.
  static <K, V> RegularImmutableMap<K, V> create(
      int n, @Nullable Object[] alternatingKeysAndValues) {
    return create(n, alternatingKeysAndValues, /* builder= */ null);
  }

  // This entry point is used by the other create method but also directly by

   * {@link MoreExecutors#directExecutor}. Normally, when the first future completes, all the other
   * tasks would be called recursively. Here, we detect that the delegate executor is executing
   * inline, and maintain a queue to dispatch tasks iteratively. There is one instance of this class
   * per call to submit() or submitAsync(), and each instance supports only one call to execute().
   *

     * @return The result data body.
     */
    protected String getResultDataBody(final String name, final String value) {
        // TODO: Support other XML footer types
        // TODO: Support other field types and trimming options
        return "<field name=\"" + XmlUtil.escapeXml(name) + "\">" + trimSpace(XmlUtil.escapeXml(value != null ? value : "")) + "</field>\n";
    }

    /**