如果你的代码需要使用PagingSource并更新数据源，那么你应该调用invalidate()方法来告知Paging库数据源已更新。但是，PagingSource类中的invalidate()方法是final的，这意味着它无法被重写。因此，你需要实现你自己的PagingSource类。

以下是一个示例，演示如何创建一个自定义PagingSource类并实现invalidate()方法：

class MyPagingSource(private val myApiService: MyApiService) : PagingSource() {

    override suspend fun load(params: LoadParams): LoadResult {
        // Implementation of load method
    }

    override val keyReuseSupported: Boolean = true

    override fun getRefreshKey(state: PagingState): Int? {
        // Implementation of getRefreshKey method
    }

    fun invalidateMyData() {
        // Implementation of invalidateMyData method
        // Call invalidate() method to notify PagingLibrary that the data has been invalidated
        invalidate()
    }
}

在这个示例中，我们创建了一个名为MyPagingSource的类，它继承自PagingSource类。我们还添加了invalidateMyData()方法，该方法调用父类的invalidate()方法以通知Paging库数据源已更新。现在，我们可以使用这个自定义的PagingSource类来获取我们的数据并通过invalidateMyData()方法来通知Paging库数据源已更新：

val myPagingSource = MyPagingSource(myApiService)

// Create a Pager object using our custom PagingSource object
val pager = Pager(
    config = PagingConfig(pageSize = 20),
    pagingSourceFactory = { myPagingSource }
)

// Observe the data
val myDataFlow = pager.flow.cachedIn(viewModelScope)
myDataFlow.collect { ... }

// Call invalidateMyData() method to notify PagingLibrary that the data has been invalidated
myPagingSource.invalidateMyData()