public static GroupBy Combine(GroupBy firstGroupBy, GroupBy secondGroupBy)
{
GroupBy groupBy = null;
bool collaps = false;
var fieldRefs = new List<FieldRef>();
if (firstGroupBy != null && firstGroupBy.FieldRefs != null)
{
collaps = firstGroupBy.Collapse;
fieldRefs.AddRange(firstGroupBy.FieldRefs);
}
if (secondGroupBy != null && secondGroupBy.FieldRefs != null)
{
collaps = collaps | secondGroupBy.Collapse;
fieldRefs.AddRange(secondGroupBy.FieldRefs);
}
if (fieldRefs.Count > 0)
{
groupBy = new GroupBy(fieldRefs, collaps);
}
return groupBy;
}