input: Write a python function to print numbers from 0 to 9.
  assert capture_output(print_numbers()) == "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n"
  assert capture_output(print_numbers()) == "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n"
output: def print_numbers():
      for i in range(10):
          print(i)