Ambiguous reference to member 'collectionView(_:numberOfItemsInSection:)' when reloading collection view data

In an app I've been writing, one of the tabs contains a Collection View that is originally filled with dummy information, but is supposed to be replaced once the user inputs some information in another tab. However, when I try to use `self.collectionView?.reloadData()` Xcode says `Ambiguous reference to member 'collectionView(_:numberOfItemsInSection:)'` . The code relevant to getting the data for the slots was removed. Does anyone here have any idea why it isn't working? ``` // // FirstViewController.swift import UIKit import Alamofire class FirstViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate { let reuseIdentifier = "cell" // also enter this string as the cell identifier in the storyboard var items = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48"] override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. self.collectionView?.reloadData() } // MARK: - UICollectionViewDataSource protocol // tell the collection view how many cells to make func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { return self.items.count } // make a cell for each cell index path func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { // get a reference to our storyboard cell let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MyCollectionViewCell // Use the outlet in our custom class to get a reference to the UILabel in the cell cell.myLabel.text = self.items[indexPath.item] cell.backgroundColor = UIColor.white cell.layer.borderColor = UIColor.white.cgColor cell.layer.borderWidth = 5 cell.layer.cornerRadius = 8// make cell more visible in our example project return cell } // MARK: - UICollectionViewDelegate protocol func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { // handle tap events print("You selected cell #\(indexPath.item)!") } ``` }