code: function(policyName)
  	{        
          var app = this;
  		var objectName = policyName;
  		var obj = {};
  		try
  		{
              if(app.policies.hasOwnProperty(policyName)){
                  obj = app.policies[policyName];
              }else{                
                  throw "not found";
              }
  		}
  		catch(e)
  		{					
  			var objFilePath = path.join(app._path,"policies",policyName);            
  			if(fs.existsSync(objFilePath+".js"))
  			{                
  				obj = require(objFilePath);				
  				if(typeof app.policies != "object") app.policies={};
  				app.policies[policyName] = obj;
  			}
  		}        
  		return obj;
  	}
docs: Get specified openbiz policy middle-ware function.
  
  This method it part of {@link openbiz.objects.Application},
  please never call this directly by ObjectService.
  
  if need to call this method, you have to use javascript's function.apply(applicationPointer,params)
  please see sample
  @memberof openbiz.services.ObjectService
  @param {string} policyName - The specified policy middle-ware name
  @returns {function}
  @example
  //below code is how to get the middle-ware of "cubi.user.ensureSomething" function
  //cubiApp is instance of openbiz.objects.Application
  var something = cubiApp.getPolicy("ensureSomething");
  @example
  //if you want to call this method directly , please try this way
  require('openbiz/services/ObjectService').getPolicy.apply(applicationPointer,policyName)