Now modify the file `main.py` to receive a body from a `PUT` request.

Declare the body using standard Python types, thanks to Pydantic.

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")

import com.google.common.collect.testing.testers.MapRemoveTester;
import com.google.common.collect.testing.testers.MapSerializationTester;
import com.google.common.collect.testing.testers.MapSizeTester;
import com.google.common.collect.testing.testers.MapToStringTester;
import com.google.common.testing.SerializableTester;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;

import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.LongBuffer;
import java.nio.ShortBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.BitSet;
import java.util.Collection;
import java.util.Comparator;
import java.util.Currency;
import java.util.Deque;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.UUID;
import java.util.function.Supplier;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.Constants;
import org.codelibs.fess.app.web.api.ApiResult;

package util

import common.BuildToolBuildJvm
import common.Os
import common.VersionedSettingsBranch
import common.javaHome
import common.requiresOs
import common.toCapitalized
import jetbrains.buildServer.configs.kotlin.AbsoluteId
import jetbrains.buildServer.configs.kotlin.BuildType
import jetbrains.buildServer.configs.kotlin.ParameterDisplay
import jetbrains.buildServer.configs.kotlin.buildSteps.exec

  "INVISIBLE_REFERENCE",
)

package okhttp3

import assertk.assertThat
import assertk.assertions.containsExactly
import assertk.assertions.hasMessage
import assertk.assertions.isEqualTo
import assertk.assertions.isIn
import java.io.IOException
import java.net.InetSocketAddress
import java.net.UnknownHostException
import java.time.Duration
import java.util.Arrays
import java.util.concurrent.TimeUnit

import java.util.List;
import java.util.Map;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.Mac;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.security.auth.kerberos.KerberosKey;

import org.bouncycastle.asn1.ASN1InputStream;

 */
package okhttp3.compare

import assertk.assertThat
import assertk.assertions.isEqualTo
import assertk.assertions.isNotNull
import assertk.assertions.isNull
import assertk.assertions.matches
import java.net.http.HttpClient
import java.net.http.HttpClient.Redirect.NORMAL
import java.net.http.HttpRequest
import java.net.http.HttpResponse.BodyHandlers
import mockwebserver3.MockResponse

 */
package org.codelibs.fess.helper;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.util.Base64;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.zip.GZIPInputStream;

 */
package okhttp3.recipes;

import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.security.GeneralSecurityException;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;