docs: def client_seed(a=random.randrange(0, 1 << SRP_KEY_SIZE)):
      """
          A: Client public key
          a: Client private key
      """
      if DEBUG:
          a = DEBUG_PRIVATE_KEY
      N, g, k = get_prime()
      A = pow(g, a, N)
      if DEBUG_PRINT:
          print('a=', binascii.b2a_hex(long2bytes(a)), end='\n')
          print('A=', binascii.b2a_hex(long2bytes(A)), end='\n')
      return A, a