public static KeyData createPrfKeyData(byte[] keyValue) throws Exception {
    return createKeyData(
        createPrfKey(keyValue), PrfConfig.PRF_TYPE_URL, KeyData.KeyMaterialType.SYMMETRIC);
  }
@return a {@code KeyData} containing a {@code HkdfPrfKey}.
java_src/src/main/java/com/google/crypto/tink/testing/TestUtil.java