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: project.rs
    path of file: ./repos/Daft/src/daft-plan/src/physical_ops
    
    the code of the file until where you have to start completion: use std::sync::Arc;

use common_error::DaftResult;
use daft_dsl::Expr;
use indexmap::IndexMap;
use itertools::Itertools;

use crate::{
    partitioning::{HashClusteringConfig, RangeClusteringConfig, UnknownClusteringConfig},
    physical_plan::PhysicalPlanRef,
    ClusteringSpec, ResourceRequest,
};
use serde::{Deserialize, Serialize};

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
pub struct Project {
    // Upstream node.
    pub input: PhysicalPlanRef,
    pub projection: Vec<Expr>,
    pub resource_request: ResourceRequest,
    pub
    
    pub fn multiline_display(&self) -> Vec<String> {
        let mut res = vec![];
        res.push(format!(
            "Project: {}",
            self.projection.iter().map(|e| e.to_string()).join(", ")
        ));
        res.push(format!(
            "Clustering spec = {{ {} }}",
            self.clustering_spec.multiline_display().join(", ")
        ));
        let resource_request = self.resource_request.multiline_display();
        if !resource_request.is_empty() {
            res.push(format!(
                "Resource request = {{ {} }}",
                resource_request.join(", ")
            ));
        }
        res
    }