Implement a Connect Four-style game engine. The board has 6 rows and 7 columns. Two players alternate turns. On each turn, the current player chooses a column. Because of gravity, the player's token falls to the lowest empty cell in that column. A move is invalid if the chosen column is already full. After each valid move, determine whether the current player has won. A player wins if they have four of their own tokens consecutively in any of the following directions: - Horizontal - Vertical - Diagonal from bottom-left to top-right - Diagonal from top-left to bottom-right Design and implement the core logic for placing a token and checking whether the latest move creates a win. Follow-up questions: 1. How would you support more than two players? 2. How would you optimize the solution if the board were very large?