App can not compile.

Hey, thanks for this insightful tutorial. I keep getting the below error when i run my application. Please help me fix this Error: public abstract androidx.lifecycle.LiveData<java.util.List<com.company.mine.data.db.unitlocalized.future.list.MetricSimpleFutureWeatherEntry>> getSimpleWeatherForecastsMetric(@org.jetbrains.annotations.NotNull()