static String getKeyType() {
    return "type.googleapis.com/google.crypto.tink.AesCmacPrfKey";
  }
This key manager generates new {@code AesCmacKeyPrf} keys and produces new instances of {@code
AesCmacPrf}.
java_src/src/main/java/com/google/crypto/tink/prf/AesCmacPrfKeyManager.java