private static void validate(AesCmacPrfParameters parameters) throws GeneralSecurityException {
    if (parameters.getKeySizeBytes() != 32) {
      throw new GeneralSecurityException("Key size must be 32 bytes");
    }
  }
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