Create a class named Wallet with one private member: double balance.

Requirements:
1. Create a default constructor Wallet() that sets balance to 0.0.
2. Create a public setter setBalance(double newBalance) that updates balance.
3. Create a public getter getBalance() that returns balance.

IMPORTANT: Do NOT write a main method. A hidden Main will create a Wallet, call setBalance(25.75), then print getBalance().

Expected Output:
25.75