A DESCRIPTION OF THE PROBLEM :
Assume we compare two maps by `equals`, where the first one is `ConcurrentHashMap`. It is important that these maps have different types of keys.
`ConcurrentHashMap` calls `get` on the second map during comparison, but it is not prepared to `ClassCastException` that can be rightfully thrown from `Map#get`.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Just run the snippet.

---------- BEGIN SOURCE ----------
```
public class Main {
    public static void main(String[] args) {
        var map = new ConcurrentHashMap<String, String>();
        map.put("key", "value");
        var map2 = new MyMap<String>();
        map2.put(1, "value");
        System.out.println(map.equals(map2));
    }

    static class MyMap<V> extends ConcurrentHashMap<Integer,V>{
        @Override
        public V get(Object key) {
            Integer newKey = (Integer)key;
            return super.get(newKey);
        }
    }
}
```
---------- END SOURCE ----------

FREQUENCY :
ALWAYS