I have the following class

```
public class DateRange
{
    private DateTime startDate;
    private DateTime endDate;
    public override bool Equals(object obj)
    {
        DateRange other = (DateRange)obj;
        if (startDate != other.startDate)
            return false;
        if (endDate != other.endDate)
            return false;
        return true;
    }
    ...
}

```

I need to store some values in a dictionary keyed with a DateRange like:

```
Dictionary<DateRange, double> tddList;

```

How should I override the `GetHashCode()` method of `DateRange` class?