code: function batchCmd(cmdArray, callback){
  
          var requestJson = [];
  
          for (var i = 0; i < cmdArray.length; i++){
              requestJson.push({
                  method: cmdArray[i][0],
                  params: cmdArray[i][1],
                  id: Date.now() + Math.floor(Math.random() * 10) + i
              });
          }
  
          var serializedRequest = JSON.stringify(requestJson);
  
          performHttpRequest(instances[0], serializedRequest, function(error, result){
              callback(error, result);
          });
  
      }
docs: Performs a batch JSON-RPC command - only uses the first configured rpc daemon /* First argument must have:
  [
  [ methodName, [params] ],
  [ methodName, [params] ]
  ]