code: @Override
      public Object read(String deviceId, String metric) {
          String translatedMetric = metricResolver.resolveMetric(metric);
  
          Client client = leshanServer.getClientRegistry().get(deviceId);
          ValueResponse leshanResponse = leshanServer.send(client, new ReadRequest(translatedMetric), 5000);
          if(leshanResponse == null) {
              return null;
          }
          return  ((LwM2mResource) leshanResponse.getContent()).getValue().value;
      }
docs: Overridden