docs: def pad(cls, data):
          """
          Pads data to match AES block size
          """
          if sys.version_info > (3, 0):
              try:
                  data = data.encode("utf-8")
              except AttributeError:
                  pass
  
              length = AES.block_size - (len(data) % AES.block_size)
              data += bytes([length]) * length
              return data
          else:
              return data + (AES.block_size - len(data) % AES.block_size) * chr(AES.block_size - len(data) % AES.block_size)