我已经在我的项目中实现了 flutterDownloader（它是一个用于在 flutter 中下载文件的包），当我像文档所说的那样将它添加到 android manifest 时，当我这样做时，gradle 会显示这个错误
**错误 ： **
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:checkDebugDuplicateClasses'.
> 1 exception was raised by workers:
java.lang.RuntimeException: Duplicate class com.google.common.util.concurrent.ListenableFuture found in modules guava-26.0-android.jar (com.google.guava:guava:26.0-android) and listenablefuture-1.0.jar (com.google.guava:listenablefuture:1.0)
Go to the documentation to learn how to <a href="d.android.com/r/tools/classpath-sync-errors">Fix dependency resolution errors</a>.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. …在我的中使用implementation 'com.google.firebase:firebase-inappmessaging-display:17.2.0'时app/build.gradle，出现以下错误：
Duplicate class com.google.common.util.concurrent.ListenableFuture found in modules guava-20.0.jar (com.google.guava:guava:20.0) and listenablefuture-1.0.jar (com.google.guava:listenablefuture:1.0)
Go to the documentation to learn how to Fix dependency resolution errors.
我的内在app/build.gradle是：
implementation 'com.google.android.gms:play-services-base:16.1.0'
implementation 'com.google.android.gms:play-services-analytics:16.0.8'
implementation 'com.google.android.gms:play-services-awareness:16.0.0'
implementation 'com.google.android.gms:play-services-cast:16.2.0'
implementation 'com.google.android.gms:play-services-gcm:16.1.0'
implementation 'com.google.android.gms:play-services-location:16.0.0'
implementation 'com.google.android.gms:play-services-maps:16.1.0'
implementation 'com.google.firebase:firebase-core:16.0.8'
implementation 'com.google.firebase:firebase-iid:17.1.2'
implementation 'com.google.firebase:firebase-messaging:17.6.0'
implementation 'android.arch.work:work-runtime:1.0.1'
implementation 'com.android.support:multidex:1.0.3'
apply plugin: 'com.google.gms.google-services'
也许我正在使用的库之一已经包含对In-App Messaging依赖的支持，然后它变得多余了？谢谢。