input: Write a python function that checks a string of parentheses. If each opening parenthesis has a matching closing parenthesis, return True. If not, return False.
  assert correct_bracketing("()")
  assert correct_bracketing("(()())")
  assert correct_bracketing("()()(()())()")
  assert correct_bracketing("()()((()()())())(()()(()))")
  assert not correct_bracketing("((()())))")
  assert not correct_bracketing(")(()")
  assert not correct_bracketing("(")
  assert not correct_bracketing("((((")
  assert not correct_bracketing(")")
  assert not correct_bracketing("(()")
  assert not correct_bracketing("()()(()())())(()")
  assert not correct_bracketing("()()(()())()))()")
output: def correct_bracketing(s):
      stack = []
      for char in s:
          if char == '(':
              stack.append(char)
          elif char == ')':
              if not stack:
                  return False
              stack.pop()
      return not stack