因此，有些第三方 ASGI 中间件的文档推荐以如下方式使用中间件：

```Python
from unicorn import UnicornMiddleware

app = SomeASGIApp()

new_app = UnicornMiddleware(app, some_config="rainbow")
```

但 FastAPI（实际上是 Starlette）提供了一种更简单的方式，能让内部中间件在处理服务器错误的同时，还能让自定义异常处理器正常运作。

为此，要使用 `app.add_middleware()` （与 CORS 中的示例一样）。

```Python
from fastapi import FastAPI
from unicorn import UnicornMiddleware

app = FastAPI()

package com.google.common.collect.testing.google;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;

package com.google.common.collect.testing.testers;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;

 */

package com.google.common.math;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;

package org.codelibs.fess.crawler.helper.impl;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;
import org.apache.tika.mime.MimeTypes;
import org.apache.tika.mime.MimeTypesFactory;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.crawler.entity.ExtractData;

 */
package org.apache.maven.artifact.transform;

import javax.inject.Inject;

import java.util.List;

import org.apache.maven.repository.legacy.resolver.transform.ArtifactTransformation;
import org.apache.maven.repository.legacy.resolver.transform.ArtifactTransformationManager;
import org.apache.maven.repository.legacy.resolver.transform.LatestArtifactTransformation;

 */

package jcifs.spnego;


import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Enumeration;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Encoding;
import org.bouncycastle.asn1.ASN1Enumerated;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1OctetString;

 */
package org.codelibs.fess.suggest.settings;

import static org.codelibs.opensearch.runner.OpenSearchRunner.newConfigs;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.util.List;
import java.util.Set;

import org.codelibs.fess.suggest.Suggester;
import org.codelibs.fess.suggest.analysis.SuggestAnalyzer;
import org.codelibs.fess.suggest.util.SuggestUtil;

import groovy.transform.CompileStatic
import japicmp.model.JApiChangeStatus
import japicmp.model.JApiClass
import japicmp.model.JApiCompatibility
import japicmp.model.JApiConstructor
import japicmp.model.JApiField
import japicmp.model.JApiHasAnnotations
import japicmp.model.JApiHasChangeStatus
import japicmp.model.JApiMethod

import java.lang.reflect.Method;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentSkipListSet;