# Advanced User Guide { #advanced-user-guide }

## Additional Features { #additional-features }

The main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

/// tip

The next sections are **not necessarily "advanced"**.

# 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,

# 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,

    /**
     * The maximum size of the client factory list.
     */
    protected int maxClientFactorySize = 10000;

    /**
     * Registers a CrawlerClientFactory with this creator.
     * All existing client mappings will be loaded into the new factory.
     * @param crawlerClientFactory The CrawlerClientFactory to register.
     */
    public synchronized void register(final CrawlerClientFactory crawlerClientFactory) {

# This file is used with all of the non-matrix tests in Jenkins.

# This .properties file defines the versions of Java with which to
# build and test Elasticsearch for this branch. Valid Java versions
# are 'java' or 'openjdk' followed by the major release number.

ES_BUILD_JAVA=jdk16

Then it will **extract** all those files and put them in a directory in your computer.

By default, it will put those files downloaded and extracted in the directory that comes with your Python installation, that's the **global environment**.

## What are Virtual Environments { #what-are-virtual-environments }

		bugLogIf(ctx, errInvalidArgument)
		return errInvalidArgument
	}

	nv := make(textproto.MIMEHeader, len(v))
	for k, kv := range v {
		// Canonicalize all headers, to remove any duplicates.
		nv[http.CanonicalHeaderKey(k)] = kv
	}

	// Save all supported headers.
	for _, supportedHeader := range supportedHeaders {
		value, ok := nv[http.CanonicalHeaderKey(supportedHeader)]
		if ok {

 * CollectionSize} present in the features specified by {@link #withFeatures(Feature...)}.
 *
 * @param <B> The concrete type of this builder (the 'self-type'). All the Builder methods of this
 *     class (such as {@link #named(String)}) return this type, so that Builder methods of more
 *     derived classes can be chained onto them without casting.

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
import org.jspecify.annotations.Nullable;

/**
 * A map entry which forwards all its method calls to another map entry. Subclasses should override
 * one or more methods to modify the behavior of the backing map entry as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in