docs: public static DeterministicKey createMasterPrivateKey(byte[] seed) throws HDDerivationException {
          checkArgument(seed.length > 8, "Seed is too short and could be brute forced");
          // Calculate I = HMAC-SHA512(key="Bitcoin seed", msg=S)
          byte[] i = HDUtils.hmacSha512(HDUtils.createHmacSha512Digest("Bitcoin seed".getBytes()), seed);
          // Split I into two 32-byte sequences, Il and Ir.
          // Use Il as master secret key, and Ir as master chain code.
          checkState(i.length == 64, i.length);
          byte[] il = Arrays.copyOfRange(i, 0, 32);
          byte[] ir = Arrays.copyOfRange(i, 32, 64);
          Arrays.fill(i, (byte)0);
          DeterministicKey masterPrivKey = createMasterPrivKeyFromBytes(il, ir);
          Arrays.fill(il, (byte)0);
          Arrays.fill(ir, (byte)0);
          // Child deterministic keys will chain up to their parents to find the keys.
          masterPrivKey.setCreationTimeSeconds(Utils.currentTimeSeconds());
          return masterPrivKey;
      }