stack.cs

public int Method1()
{
    int value = 10;
    Incrementer inc = new Incrementer(value);
    inc.Increment();
    inc.Increment();
    return value;
}

public class Incrementer {
    private int _value;

    public Incrementer(int value) => _value = value;

    public int Increment() => _value + 1;
}