code: public byte[] hash(byte[] data) throws SdkClientException {
          try {
              MessageDigest md =  getMessageDigestInstance();
              md.update(data);
              return md.digest();
          } catch (Exception e) {
              throw new SdkClientException(
                      "Unable to compute hash while signing request: "
                              + e.getMessage(), e);
          }
      }
docs: Hashes the binary data using the SHA-256 algorithm.
  
  @param data
  The binary data to hash.
  
  @return The hashed bytes from the specified data.
  
  @throws SdkClientException
  If the hash cannot be computed.