public static Key createKey(
      KeyData keyData, int keyId, KeyStatusType status, OutputPrefixType prefixType)
      throws Exception {
    return Key.newBuilder()
        .setKeyData(keyData)
        .setStatus(status)
        .setKeyId(keyId)
        .setOutputPrefixType(prefixType)
        .build();
  }
@return a key with some specified properties.
java_src/src/main/java/com/google/crypto/tink/testing/TestUtil.java