object IQueryProvider.Execute(Expression expression)
 {
     Check.NotNull <Expression>(expression, nameof(expression));
     return(ObjectQueryProvider.ExecuteSingle <object>(Enumerable.Cast <object>(this.CreateQuery(expression, expression.Type)), expression));
 }
 TResult IQueryProvider.Execute <TResult>(Expression expression)
 {
     Check.NotNull <Expression>(expression, nameof(expression));
     return(ObjectQueryProvider.ExecuteSingle <TResult>((IEnumerable <TResult>) this.CreateQuery <TResult>(expression), expression));
 }