Kotlin 协程单元测试失败并显示Module with the Main dispatcher had failed to initialize

在运行kotlin suspend方法的单元测试时(使用withContext(Dispatchers.Main))，测试方法失败，出现以下异常:

My coroutine lib versions are kotlinx-coroutines-core:1.1.1 and kotlinx-coroutines-android:1.1.1

Example:

suspend fun methodToTest() {
        withContext(Dispatchers.Main) {
           doSomethingOnMainThread()
                val data = withContext(Dispatchers.IO) {
                    doSomethingOnIOThread()
                }
        }
    }

而且，当我移除withContext(Dispatchers.Main)时，效果很好.

java.lang.IllegalStateException: Module with the Main dispatcher had failed to initialize. For tests Dispatchers.setMain from kotlinx-coroutines-test module can be used

at kotlinx.coroutines.internal.MissingMainCoroutineDispatcher.missing(MainDispatchers.kt:79)
at kotlinx.coroutines.internal.MissingMainCoroutineDispatcher.isDispatchNeeded(MainDispatchers.kt:54)
at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:373)
at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:25)
at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:152)
at kotlinx.coroutines.BuildersKt.withContext(Unknown Source)