You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sort.rs
    path of file: ./repos/polars/crates/polars-lazy/src/physical_plan/executors
    
    the code of the file until where you have to start completion: use super::*;

pub(crate) struct SortExec {
    pub(crate) input: Box<dyn Executor>,
    pub(crate) by_column: Vec<Arc<dyn PhysicalExpr>>,
    pub(crate) args: SortArguments,
}

impl SortExec {
    fn execute_impl(
        &mut self,
        state: &ExecutionState,
        mut df: DataFrame,
    ) -> PolarsResult<DataFrame> {
        state.should_stop()?;
        df.as_single_chunk_par();

        let by_columns = self
            .by_column
            .iter()
            .enumerate()
            .map(|(i, e)| {
                let mut s = e.evaluate(&df, state)?;
                // Polars core will try to set the sorted columns as sorted.
                // 
    
    fn execute(&mut self, state: &mut ExecutionState) -> PolarsResult<DataFrame> {
        #[cfg(debug_assertions)]
        {
            if state.verbose() {
                println!("run SortExec")
            }
        }
        let df = self.input.execute(state)?;

        let profile_name = if state.has_node_timer() {
            let by = self
                .by_column
                .iter()
                .map(|s| Ok(s.to_field(&df.schema())?.name))
                .collect::<PolarsResult<Vec<_>>>()?;
            let name = comma_delimited("sort".to_string(), &by);
            Cow::Owned(name)
        } else {
            Cow::Borrowed("")
        };

        if state.has_node_timer() {
            let new_state = state.clone();
            new_state.record(|| self.execute_impl(state, df), profile_name)
        } else {
            self.execute_impl(state, df)
        }
    }