Error Handling Swift

import UIKit

var str = "Hello, playground"

struct Auth{
    func authenticateUser(username: String) -> Bool {
        return username.uppercased() == "PSLV" ? true : false
    }
    
    func verifyUser(username: String) throws -> Bool{
        return username.uppercased() == "PSLV" ? true : false
    }
}

let user1 = Auth()
user1.authenticateUser(username: "slv") //false
user1.authenticateUser(username: "PSLV") //true

try user1.verifyUser(username: "slv") //false
try user1.verifyUser(username: "pslv") //true

do {
    try user1.verifyUser(username: "SLV") //false
} catch  {
    print("username wrong")
}

do {
    try user1.verifyUser(username: "pSLV") //true
} catch  {
    print("username wrong")
}