public new ExpressValue this[string pKey] {
get {
if (base[pKey] != null)
{
ExpressValue val = base[pKey] as ExpressValue;
return(val);
}
else
{
return(null);
}
}
}
public ExpressValue Add(ExpressValue pExpress)
{
this.Add(pExpress.Name, pExpress);
return(pExpress);
}