function RetryPolicyFilter(retryCount, retryInterval) {
  this.retryCount = retryCount ? retryCount : RetryPolicyFilter.DEFAULT_CLIENT_RETRY_COUNT;
  this.retryInterval = retryInterval ? retryInterval : RetryPolicyFilter.DEFAULT_CLIENT_RETRY_INTERVAL;
}
Creates a new RetryPolicyFilter instance.
@class
The RetryPolicyFilter allows you to retry operations,
using a custom retry policy. Users are responsible to 
define the shouldRetry method.
To apply a filter to service operations, use `withFilter`
and specify the filter to be used when creating a service.
@constructor
@param {number} [retryCount=30000]        The client retry count.
@param {number} [retryInterval=3]     The client retry interval, in milliseconds.

@example
var azure = require('azure-storage');
var retryPolicy = new azure.RetryPolicyFilter();
retryPolicy.retryCount = 3;
retryPolicy.retryInterval = 3000;
retryPolicy.shouldRetry = function(statusCode, retryContext) {

};
var blobService = azure.createBlobService().withFilter(retryPolicy);