This rule raises an issue when a private nested class is never used.

## Why is this an issue?

`private` classes that are never used are dead code: unnecessary, inoperative code that should be removed. Cleaning out dead code decreases the size of the maintained codebase, making it easier to understand the program and preventing bugs from being introduced.

### Code examples

### Noncompliant code example

    public class TopLevel
    {
      private class Nested {...} // Noncompliant: Nested is never used
    }

#### Compliant solution

    public class TopLevel
    {
      void doSomething() {
        Nested a = new Nested();
        ...
      }
      private class Nested {...}
    }