Simulate a simple bank system that supports basic operations like deposit, withdraw, and check balance for different accounts. You will implement methods to handle these transactions and ensure validity based on account balances and existence.

You are given file paths and their content. Find and return groups of duplicate files based on their content.

Simulate the Game of Life, updating the state of a board based on the rules of cell survival and death in each generation. Modify the board in place to represent the next generation.