private static Map<String, Parameters> namedParameters() throws GeneralSecurityException {
        Map<String, Parameters> result = new HashMap<>();
        result.put(
            "AES128_CTR_HMAC_SHA256_4KB",
            PredefinedStreamingAeadParameters.AES128_CTR_HMAC_SHA256_4KB);
        result.put(
            "AES128_CTR_HMAC_SHA256_1MB",
            PredefinedStreamingAeadParameters.AES128_CTR_HMAC_SHA256_1MB);
        result.put(
            "AES256_CTR_HMAC_SHA256_4KB",
            PredefinedStreamingAeadParameters.AES256_CTR_HMAC_SHA256_4KB);
        result.put(
            "AES256_CTR_HMAC_SHA256_1MB",
            PredefinedStreamingAeadParameters.AES256_CTR_HMAC_SHA256_1MB);
        return Collections.unmodifiableMap(result);
  }
This key manager generates new {@code AesCtrHmacStreamingKey} keys and produces new instances of
{@code AesCtrHmacStreaming}.
java_src/src/main/java/com/google/crypto/tink/streamingaead/AesCtrHmacStreamingKeyManager.java