driver-core/src/main/com/mongodb/internal/connection/BaseCluster.java
private Random getRandom() {
        Random result = random.get();
        if (result == null) {
            result = new Random();
            random.set(result);
        }
        return result;
    }
private Random getRandom() {
        Random result = random.get();
        if (result == null) {
            result = new Random();
            random.set(result);
        }
        return result;
    }
initialValue() method.