receipt-manager.js

class ReceiptManager {
 
    _generateReceiptHtml(orderId, userEmail) {
        // generates and returns HTML of the receipt
    }
    
 
    sendReceipt(orderId, userEmail, sendStrategy) {
        const receiptHTML = this._generateReceiptHtml(orderId, userEmail);
        sendStrategy.send(receiptHTML, userEmail);
    }
}