public virtual ObjectResult<Employee_Sales_by_Country_Result> Employee_Sales_by_Country(Nullable<System.DateTime> beginning_Date, Nullable<System.DateTime> ending_Date)
{
var beginning_DateParameter = beginning_Date.HasValue ?
new ObjectParameter("Beginning_Date", beginning_Date) :
new ObjectParameter("Beginning_Date", typeof(System.DateTime));
var ending_DateParameter = ending_Date.HasValue ?
new ObjectParameter("Ending_Date", ending_Date) :
new ObjectParameter("Ending_Date", typeof(System.DateTime));
return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<Employee_Sales_by_Country_Result>("Employee_Sales_by_Country", beginning_DateParameter, ending_DateParameter);
}