private static IDictionary <string, object> ExpandoGroupBy <T>(T x, string[] columnsToGroup) where T : class
{
var groupByColumns = new System.Dynamic.ExpandoObject() as IDictionary <string, object>;
groupByColumns.Clear();
foreach (string column in columnsToGroup)
{
groupByColumns.Add(column, typeof(T).GetProperty(column).GetValue(x, null));
}
return(groupByColumns);
}