/// <summary>Saves the state to a stream (that is, serializes it).</summary>
/// <param name="s">the stream</param>
/// <exception cref="System.IO.IOException">if an I/O error occurs</exception>
/// <serialData>
/// The current value is emitted (a
/// <c>double</c>
/// ).
/// </serialData>
private void WriteObject(ObjectOutputStream s)
{
s.DefaultWriteObject();
s.WriteDouble(Get());
}