code: function spyGlobalVar(varName, callback) {
  			phantomas.log('spy: attaching to %s global variable', varName);
  
  			window.__defineSetter__(varName, function(val) {
  				phantomas.log('spy: %s global variable has been defined', varName);
  
  				spiedGlobals[varName] = val;
  				callback(val);
  			});
  
  			window.__defineGetter__(varName, function() {
  				return spiedGlobals[varName] || undefined;
  			});
  
  		}
docs: call given callback when "varName" global variable is being defined used by jQuery module