private static Map<String, Parameters> namedParameters() throws GeneralSecurityException {
        Map<String, Parameters> result = new HashMap<>();
        result.put("AES128_GCM_HKDF_4KB", PredefinedStreamingAeadParameters.AES128_GCM_HKDF_4KB);
        result.put("AES128_GCM_HKDF_1MB", PredefinedStreamingAeadParameters.AES128_GCM_HKDF_1MB);
        result.put("AES256_GCM_HKDF_4KB", PredefinedStreamingAeadParameters.AES256_GCM_HKDF_4KB);
        result.put("AES256_GCM_HKDF_1MB", PredefinedStreamingAeadParameters.AES256_GCM_HKDF_1MB);
        return Collections.unmodifiableMap(result);
  }
This key manager generates new {@code AesGcmHkdfStreamingKey} keys and produces new instances of
{@code AesGcmHkdfStreaming}.
java_src/src/main/java/com/google/crypto/tink/streamingaead/AesGcmHkdfStreamingKeyManager.java