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: price.rs
    path of file: ./repos/scryfall-rs/src/card
    
    the code of the file until where you have to start completion: //! Module defining a price object containing data in various currencies.
use std::cmp::Ordering;

use serde::{Deserialize, Serialize};

/// Struct defining a price object containing data in various currencies.
#[derive(Serialize, Deserialize, Clone, Eq, PartialEq, Hash, Debug, Default)]
#[allow(missing_docs)]
pub struct Price {
    pub usd: Option<String>,
    pub usd_foil: Option<String>,
    pub eur: Option<String>,
    pub eur_foil: Option<String>,
    pub tix: Option<String>,
}

impl Price {
    /// Creates an array of component prices that can be iterated over.
    fn to_array(&self) -> [&Option<String>; 5] {
        [
     
    
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        let mut result = None;
        for (a, b) in self.to_array().iter().zip(other.to_array().iter()) {
            match (result, compare_prices(a, b)) {
                // If either ordering is `None`, use the other. Then if either is `Some(Equal)`,
                // use the other.
                (None, order)
                | (order, None)
                | (Some(Ordering::Equal), order)
                | (order, Some(Ordering::Equal)) => {
                    result = order;
                },
                // If the two orderings already agree, do nothing.
                (Some(a), Some(b)) if a == b => {},
                // Otherwise, they disagree, so these prices cannot be ordered.
                _ => return None,
            }
        }
        result
    }