input: Write a function to generate all permutations of a string using itertools.
  assert generate_permutations('ABC') == [('A', 'B', 'C'), ('A', 'C', 'B'), ('B', 'A', 'C'), ('B', 'C', 'A'), ('C', 'A', 'B'), ('C', 'B', 'A')]
  assert generate_permutations('AB') == [('A', 'B'), ('B', 'A')]
  assert generate_permutations('A') == [('A',)]
output: def generate_permutations(s):
      from itertools import permutations
      return list(permutations(s))