code: def keypair_from_seed(seed, index=0):
      
  
      h = blake2b(digest_size=32)
      h.update(seed + struct.pack(">L", index))
      priv_key = h.digest()
      pub_key = private_to_public_key(priv_key)
      return {'private': priv_key, 'public': pub_key}
docs: Generates a deterministic keypair from `seed` based on `index`
  
      :param seed: bytes value of seed
      :type seed: bytes
  
      :param index: offset from seed
      :type index: int
  
      :return: dict of the form: {
          'private': private_key
          'public': public_key
      }