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: column_selection.rs
    path of file: ./repos/pueue/pueue/src/client/query
    
    the code of the file until where you have to start completion: use anyhow::Result;
use pest::iterators::Pair;

use super::{QueryResult, Rule};

pub fn apply(section: Pair<'_, Rule>, query_result: &mut QueryResult) -> Result<()> {
    // This query is expected to be structured like this:
    // `columns = [(column (, column)*]`
    let mut columns_pairs = section.into_inner();
    // Pop the `column` and `=`
    let _columns_word = columns_pairs.next().unwrap();
    let _equals = columns_pairs.next().unwrap();

    // Ge
    
pub fn apply(section: Pair<'_, Rule>, query_result: &mut QueryResult) -> Result<()> {
    // This query is expected to be structured like this:
    // `columns = [(column (, column)*]`
    let mut columns_pairs = section.into_inner();
    // Pop the `column` and `=`
    let _columns_word = columns_pairs.next().unwrap();
    let _equals = columns_pairs.next().unwrap();

    // Get the list of columns.
    let multiple_columns = columns_pairs.next().unwrap();
    // Extract all columns from the multiple_columns.inner iterator
    // The structure is like this
    // ```
    // Pair {
    //  rule: multiple_columns,
    //  span: Span {
    //      str: "id,status",
    //      start: 7,
    //      end: 16,
    //  },
    //  inner: [
    //      Pair {
    //          rule: column,
    //          span: Span {
    //              str: "id",
    //              start: 7,
    //              end: 9,
    //          },
    //          inner: [
    //              Pair {
    //                  rule: id,
    //                  span: Span {
    //                      str: "id",
    //                      start: 7,
    //                      end: 9,
    //                  },
    //                  inner: [],
    //              },
    //          ],
    //      },
    //      ...
    //      ]
    // }
    // ```
    let mut columns = multiple_columns
        .into_inner()
        .map(|pair| pair.into_inner().next().unwrap().as_rule())
        .collect::<Vec<Rule>>();

    query_result.selected_columns.append(&mut columns);

    Ok(())
}