## Why is this an issue?

A nested type is a type argument that is also a generic type. Calling a method with such a nested type argument requires complicated and confusing code. It should be avoided as much as possible.

### Noncompliant code example

    using System;
    using System.Collections.Generic;

    namespace MyLibrary
    {
      public class Foo
      {
        public void DoSomething(ICollection<ICollection<int>> outerCollect) // Noncompliant
        {
        }
      }
    }