input: Write a function to find the intersection of two sets of integers. The function should take two sets as input and return the intersection of those sets. If the input sets are empty, the function should return an empty set.
  assert intersection({1, 2, 3, 4}, {3, 4, 5, 6})=={3, 4}
  assert intersection({1, 2, 3}, {4, 5, 6})==set()
  assert intersection({1, 2, 3}, {2, 3, 4})=={2, 3}
  assert intersection({}, {1, 2, 3})==set()
  assert intersection({}, {})==set()
output: def intersection(set1, set2):
      return set1 & set2