Guard Clauses & Honest Names

Refactor (re-implement) static int shipFee(int weightGrams, boolean vip, String country) — behavior frozen by these tests, but the implementation must use GUARD CLAUSES (no else-nesting) and the local variables must carry meaningful names: - country not "VN" or "SG" → IllegalArgumentException - weight <= 0 → IllegalArgumentException - base fee: 400 cents; plus 200 if weight > 2000 - vip: 50% off the running total (integer division) The grader checks behavior AND structure: the method must not contain an else branch and must use a variable named feeCents.

Difficulty: intermediate