code: @Override
    public EphemeralKey deserialize(JsonElement json, Type typeOfT,
        JsonDeserializationContext context)
        throws JsonParseException {
      Gson gson = new GsonBuilder()
          .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
          .create();
  
      EphemeralKey result = gson.fromJson(json, EphemeralKey.class);
      result.setRawJson(json.getAsJsonObject().toString());
      return result;
    }
docs: Deserializes an ephemeral_key JSON payload into an {@link EphemeralKey} object.