Implement a function that determines whether a set of poker cards contains a **straight flush**. You are given a list of unique playing cards. Each card has: - a **rank**: one of `2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K, A` - a **suit**: one of `Spades, Hearts, Diamonds, Clubs` A **straight flush** is a set of 5 cards that: 1. all have the same suit, and 2. have 5 consecutive ranks. Assume: - `A` may be used either as low in `A-2-3-4-5` or as high in `10-J-Q-K-A` - the input contains no duplicate cards Return `true` if at least one straight flush exists in the given cards, otherwise return `false`. Example: - Input: `[(10, Hearts), (J, Hearts), (Q, Hearts), (K, Hearts), (A, Hearts), (3, Clubs)]` - Output: `true` - Input: `[(2, Spades), (3, Spades), (4, Spades), (5, Spades), (7, Spades)]` - Output: `false`