Extending inner java class with generics in kotlin

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1

Have no ideas how to extend the following java inner class Context (can’t change it)

public class Mapper<KEYIN, VALUEIN, KEYOUT, VALUEOUT>

      public abstract class Context
        implements MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> { }

code in Kotlin:

class MapperContext<T>(sc: JavaSparkContext) : Mapper<LongWritable, Text, Text, T>.Context(), Serializable{

compiles with : Error:(36, 70) Kotlin: Unresolved reference: Context.
How could I resolve this issue?