Method distinct

datafusion/functions-aggregate/src/string_agg.rs:707–710

(mut self)

            }
        }
        fn distinct(mut self) -> Self {
            self.distinct = true;
            self
        }

        fn order_by_col(mut self, col: &str, sort_options: SortOptions) -> Self {
            self.order_bys.extend([PhysicalSortExpr::new(