input: Write a python function to check if a given object is a list or a tuple.
  assert check_type([]) == "list"
  assert check_type(()) == "tuple"
  assert check_type([1, 2, 3]) == "list"
  assert check_type((1, 2, 3)) == "tuple"
output: def check_type(obj):
      if isinstance(obj, list):
          return "list"
      elif isinstance(obj, tuple):
          return "tuple"