public static KeyData createAesCtrHmacStreamingKeyData(
      byte[] keyValue, int derivedKeySize, int ciphertextSegmentSize) throws Exception {
    HmacParams hmacParams = HmacParams.newBuilder().setHash(HashType.SHA256).setTagSize(16).build();
    AesCtrHmacStreamingParams keyParams =
        AesCtrHmacStreamingParams.newBuilder()
            .setCiphertextSegmentSize(ciphertextSegmentSize)
            .setDerivedKeySize(derivedKeySize)
            .setHkdfHashType(HashType.SHA256)
            .setHmacParams(hmacParams)
            .build();
    AesCtrHmacStreamingKey keyProto =
        AesCtrHmacStreamingKey.newBuilder()
            .setVersion(0)
            .setKeyValue(ByteString.copyFrom(keyValue))
            .setParams(keyParams)
            .build();
    return createKeyData(
        keyProto,
        StreamingAeadConfig.AES_CTR_HMAC_STREAMINGAEAD_TYPE_URL,
        KeyData.KeyMaterialType.SYMMETRIC);
  }
@return a {@code KeyData} containing a {@code AesCtrHmacStreamingKey}.
java_src/src/main/java/com/google/crypto/tink/testing/TestUtil.java