This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.base;

import static org.codelibs.core.stream.StreamUtil.stream;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.codelibs.core.lang.StringUtil;

 * the License.
 */

package com.google.common.cache;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.collect.ForwardingObject;
import com.google.common.collect.ImmutableMap;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkState;
import static java.util.Collections.synchronizedSet;
import static java.util.Collections.unmodifiableSet;

import com.google.common.base.Equivalence;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Map;

 * the License.
 */

package com.google.common.io;

import static com.google.common.io.Files.simplifyPath;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Files#simplifyPath}.
 *

 * the License.
 */

package com.google.common.io;

import static com.google.common.io.Files.simplifyPath;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Files#simplifyPath}.
 *

 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.collect.Maps;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.escape;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import javax.annotation.CheckForNull;

/**
 * An {@link Escaper} that converts literal text into a format safe for inclusion in a particular

package com.google.common.primitives;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Converter;
import com.google.errorprone.annotations.InlineMe;

package com.google.common.primitives;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Converter;
import com.google.errorprone.annotations.InlineMe;