code: function httpGet(parentSpan, urlString, callback) {
      var span = opentracing.globalTracer().startSpan('http.get', { childOf : parentSpan });
      var callbackWrapper = function (err, data) {
          span.finish();
          callback(err, data);
      };
  
      try {
          var carrier = {};
          opentracing.globalTracer().inject(span, opentracing.FORMAT_TEXT_MAP, carrier);
  
          var dest = url.parse(urlString);
          var options = {
              host : PROXY_HOST,
              path : dest.path,
              port : PROXY_PORT,
              headers: {
                  // User-Agent is required by the GitHub APIs
                  'User-Agent': 'LightStep Example',
              }
          };
          for (var key in carrier) {
              options.headers[key] = carrier[key];
          }
  
          // Create a span representing the https request
          span.setTag('url', urlString);
          span.log({
              event : 'options',
              'options': options,
          });
          return http.get(options, function(response) {
              var bodyBuffer = '';
              response.on('data', function(chunk) {
                  bodyBuffer += chunk;
              });
              response.on('end', function() {
                  span.log({
                      body   : bodyBuffer,
                      length : bodyBuffer.length,
                  });
  
                  var parsedJSON, err;
                  try {
                      parsedJSON = JSON.parse(bodyBuffer);
                  } catch (exception) {
                      err = {
                          buffer    : bodyBuffer,
                          exception : exception,
                      };
                      span.setTag('error', true);
                      span.log({
                          event : 'error',
                          'error.object': err,
                      });
                  }
  
                  callbackWrapper(err, parsedJSON);
              });
          });
      } catch (exception) {
          span.setTag('error', true);
          span.log({
              event : 'error',
              'error.object': exception,
          });
          callbackWrapper(exception, null);
      }
  }
docs: Helper function to make a GET request and return parsed JSON data.