code: private static int postRUM(String apiKey, String jsonPayload) {
      try {
        if (validateApiKey(apiKey)) {
          String endpoint = RaygunSettings.getRUMEndpoint();
          MediaType MEDIA_TYPE_JSON = MediaType.parse("application/json; charset=utf-8");
  
          OkHttpClient client = new OkHttpClient.Builder()
              .connectTimeout(NETWORK_TIMEOUT, TimeUnit.SECONDS)
              .writeTimeout(NETWORK_TIMEOUT, TimeUnit.SECONDS)
              .readTimeout(NETWORK_TIMEOUT, TimeUnit.SECONDS)
              .build();
  
          RequestBody body = RequestBody.create(MEDIA_TYPE_JSON, jsonPayload);
  
          Request request = new Request.Builder()
              .url(endpoint)
              .header("X-ApiKey", apiKey)
              .post(body)
              .build();
  
          Response response = null;
  
          try {
            response = client.newCall(request).execute();
            RaygunLogger.d("RUM HTTP POST result: " + response.code());
            return response.code();
          } catch (IOException ioe) {
            RaygunLogger.e("OkHttp POST to Raygun RUM backend failed - " + ioe.getMessage());
            ioe.printStackTrace();
          } finally {
            if (response != null) response.body().close();
          }
        }
      } catch (Exception e) {
        RaygunLogger.e("Can't post to RUM. Exception - " + e.getMessage());
        e.printStackTrace();
      }
      return -1;
    }
docs: Raw post method that delivers a pre-built RUM payload to the Raygun API.
  
  @param apiKey      The API key of the app to deliver to
  @param jsonPayload The JSON representation of a ??? to be delivered over HTTPS.
  @return HTTP result code - 202 if successful, 403 if API key invalid, 400 if bad message (invalid properties)