/// <summary>
/// Fills the list provided with the element matching the filter provided
/// </summary>
/// <param name="retVal">The list to be filled with the element matching the condition expressed in the filter</param>
/// <param name="filter">The filter to apply</param>
public override void Fill(List <INamable> retVal, BaseFilter filter)
{
Expression.Fill(retVal, filter);
InitialValue.Fill(retVal, filter);
Condition.Fill(retVal, filter);
}