y'all I'm getting a "nil" response with swift 4's new decodable

airbnbCodable.swift

//: Playground - noun: a place where people can play

import Foundation
import PlaygroundSupport


// Struct

struct Listing {
    let name: String
    let city: String
    let bedrooms: Int
    let price: Int
    let thumbnail: URL
    let id: Int
    
    init(name: String, city: String, bedrooms: Int, price: Int, thumbnail: URL, id: Int) {
        self.name = name
        self.city = city
        self.bedrooms = bedrooms
        self.price = price
        self.thumbnail = thumbnail
        self.id = id
    }
}

extension Listing: Decodable {
    
    // declaring our keys
    
    enum Keys: String, CodingKey {
        case listing = "listing"
        case pricing = "pricing_quote"
    }
    
    enum ListingKeys: String, CodingKey {
        case name = "name"
        case city = "city"
        case bedrooms = "bedrooms"
        case id = "id"
        case thumbnail = "picture_url"
    }
    
    enum PriceKeys: String, CodingKey {
        case nightly_price = "localized_nightly_price"
    }
    
    init(from decoder: Decoder) throws {
        
        // defining our keyed container
        let container = try decoder.container(keyedBy: Keys.self)
        
        // Listing Keys - contains all info about listing
        let listingContainer = try container.nestedContainer(keyedBy: ListingKeys.self, forKey: .listing)
        
        // Info within the Listing Keys -
        let name: String = (try listingContainer.decodeIfPresent(String.self, forKey: .name))!
        let city: String = (try listingContainer.decodeIfPresent(String.self, forKey: .city))!
        let bedrooms: Int = (try listingContainer.decodeIfPresent(Int.self, forKey: .bedrooms))!
        let id: Int = (try listingContainer.decodeIfPresent(Int.self, forKey: .id))!
        let thumbnail: URL = (try listingContainer.decodeIfPresent(URL.self, forKey: .thumbnail))!
        
        // Price Keys - contains info about nightly price
        let priceContainer = try container.nestedContainer(keyedBy: PriceKeys.self, forKey: .pricing)
        
        // Info within Price Keys -
        let price: Int = (try priceContainer.decodeIfPresent(Int.self, forKey: .nightly_price))!
        
        self.init(name: name, city: city, bedrooms: bedrooms, price: price, thumbnail: thumbnail, id: id)
    }
}

struct RentalList : Decodable {
    let data: [Listing]
}

typealias JSON = [String: Any]

// Network Request

enum NetworkError: Error {
    case unknown
    case couldNotParseJSON
}

class Networking {
    
    let session = URLSession.shared
    
    let url = URL(string:"https://api.airbnb.com/v2/search_results?key=915pw2pnf4h1aiguhph5gc5b2")!
    
    func getListing(id: Int, completion: @escaping ([Listing]) -> Void) {
        
        let request = URLRequest(url: url)
        session.dataTask(with: request) { (data, resp, err) in
            if let data = data {
                
                let rentalList = try? JSONDecoder().decode(RentalList.self, from: data) // returning nil instead of JSON object
                
                guard let listings = rentalList?.data else {return}
                completion(listings)
            }
        }.resume()
    }
}

// return a listing
let networking = Networking()
networking.getListing(id: 861986, completion: { (res) in
    print(res)
})

// Error Handling



PlaygroundPage.current.needsIndefiniteExecution = true