Nested generic parameter IList <IList <Object >> how to pass parameters

When calling third-party libraries, there is such a generic parameter, as shown below:

 

 

According to experience, the use of two nested List can declare variables:

IList<IList<AnnotatedPoint2D>>  outImageGrid2 = new List<List<AnnotatedPoint2D>>();

// here hint to the compiler error: can not implicitly convert .

Finally, find a solution in stackflow:

IList<IList<AnnotatedPoint2D>>  outImageGrid2 = new List<IList<AnnotatedPoint2D>>();