input: def cycpattern_check(a, b):
      """Given two strings, check if the second string or any of its cyclic permutations is a substring within the first string.
      cycpattern_check("abcd", "abd") => False
      cycpattern_check("hello", "ell") => True
      cycpattern_check("whassup", "psus") => False
      cycpattern_check("abab", "baa") => True
      cycpattern_check("efef", "eeff") => False
      cycpattern_check("himenss", "simen") => True
  
      """
output:     
      if not b:
          return True
      if not a:
          return False
          
      len_b = len(b)
      for i in range(len_b):
          cyclic_b = b[i:] + b[:i]
          if cyclic_b in a:
              return True
      return False
  