title: Nan::AsyncQueue is failed at runtime
body: <p>Hi I am learning addon implementation. I am getting the error below.</p>
  
  <p>This error coming from js file:</p>
  
  <blockquote>
    <p>vec1.add_number(20,function(err,res)) SyntaxError: Unexpected token )</p>
  </blockquote>
  
  <p>index.js:   </p>
  
  <pre><code>var m = require('./');
     var vec1 = new  m.Vector(20, 10, 0); // call to new
     vec1.add_number(20,function(err,res)) // **here is the error pls help to fix**
      {
      if(err)
      console.error(err);
      else
      console.log('Final Result=%d',res);
  </code></pre>
  
  <p>testworker.cc</p>
  
  <pre><code>#include&lt;nan.h&gt;
  #include  "testWorker.h"
  #include&lt;iostream&gt;
  void TestWorker::Execute()
  {
   std::cout&lt;&lt;"its Execition\n";
   myNumber +=6;
  }
  
  void TestWorker::Handleokcallback()
  {
  std::cout&lt;&lt;"Enter to Handleokcallback\n";
  Nan::HandleScope scope;
  auto numberjs= Nan::New(myNumber);
  v8::local&lt;v8::Value&gt; argv[] ={Nan::Undefined,numberjs};
  myCallback-&gt;call(2,argv);    
  }
  </code></pre>
  
  <h2>Here is the error logs</h2>
  
  <p>module.js:435
    return process.dlopen(module, path._makeLong(filename));
                   ^</p>
  
  <p>Error: /home/admin1/Desktop/node-addon-tutorial-master/VectorExample/build/Release/myModule.node: undefined symbol: _ZTV10TestWorker
      at Error (native)
      at Object.Module._extensions..node (module.js:435:18)
      at Module.load (module.js:344:32)
      at Function.Module._load (module.js:301:12)
      at Module.require (module.js:354:17)
      at require (internal/module.js:12:17)
      at Object. (/home/admin1/Desktop/node-addon-tutorial-master/VectorExample/bindings.js:6:13)
      at Module._compile (module.js:410:26)
      at Object.Module._extensions..js (module.js:417:10)
      at Module.load (module.js:344:32)</p>