input: Write a function to find the intersection of two sets.
  assert intersection({1, 2, 3}, {2, 3, 4}) == {2, 3}
  assert intersection({10, 20, 30}, {30, 40, 50}) == {30}
  assert intersection({5, 6, 7}, {8, 9, 10}) == set()
output: def intersection(set1, set2):
      return set1 & set2