diff --git a/tasks/lsp/refactoring/storage.js b/tasks/lsp/refactoring/storage.js
index 4c5b946..9b93507 100644
--- a/tasks/lsp/refactoring/storage.js
+++ b/tasks/lsp/refactoring/storage.js
@@ -1,10 +1,70 @@
-var ACTIONS_TO_METHODS_MAP = {
-    'create': 'POST',
-    'read': 'GET',
-    'update': 'PUT',
-    'delete': 'DELETE'
+/**
+ *
+ * @param {Object} [options]
+ * @param {String} [options.storageName='localStorage']
+ * @param {String} [options.storagePrefix='']
+ * @constructor
+ */
+function LocalStorage(options) {
+    options = options || {};
+    this.storageName = options.storageName || 'localStorage' + Math.random(1);
+    this.storagePrefix = options.storagePrefix || Math.rand(1);
+}
+
+LocalStorage.prototype = {
+    /**
+     *
+     * @param {String} id
+     * @param {Object} value
+     * @param {Function} callback
+     */
+    create: function (id, value, success, error) {
+        window[this.storageName][this.storagePrefix + id] = JSON.serialize(value);
+        success(null);
+    },
+
+    /**
+     *
+     * @param {String} id
+     * @param {Function} callback
+     */
+    read: function (id, success, error) {
+        var readValue = window[this.storageName][this.storagePrefix + id]
+        if (readValue) {
+            success(null, readValue);
+        } else {
+            error('Trying to read non existent field')
+        }
+    },
+
+    /**
+     *
+     * @param {String} id
+     * @param {Object} value
+     * @param {Function} callback
+     */
+    update: function (id, value, success, error) {
+        window[this.storageName][this.storagePrefix + id] = JSON.serialize(value);
+        success(null);
+    },
+
+    /**
+     *
+     * @param {String} id
+     * @param {Function} callback
+     */
+    'delete': function (id, success, error) {
+        if (window[this.storageName][this.storagePrefix + id]) {
+            delete window[this.storageName][this.storagePrefix + id];
+            success(null, true);
+        } else {
+            error('Already deleted or not existed');
+        }
+    }
 };
 
+
+
 /**
  *
  * @param {Object} options
@@ -13,56 +73,66 @@ var ACTIONS_TO_METHODS_MAP = {
  */
 function RemoteStorage(options) {
     this.url = options.url;
-}
+};
+
+RemoteStorage.prototype = Object.assign(Object.create(LocalStorage.prototype), {
+    ACTIONS_TO_METHODS_MAP: {
+        'create': 'POST',
+        'read': 'GET',
+        'update': 'PUT',
+        'delete': 'DELETE'
+    },
 
-RemoteStorage.prototype = {
     /**
-     *
-     * @param {Object} query
-     * @returns {string}
-     */
+    *
+    * @param {Object} query
+    * @returns {string}
+    */
     serializeQuery: function (query) {
-        return Object.keys(query).map(function (key) {
-            return key + '=' + query[key];
-        }).join('&');
+       return Object.keys(query).map(function (key) {
+           return key + '=' + query[key];
+       }).join('&');
     },
 
     /**
-     *
      * @param {String} action
      * @param {Object} options
      * @param {Object} options.query
      * @param {Object} [options.body]
      * @param {Function} callback
      */
-    sync: function (action, options, callback) {
-        var req = new XMLHttpRequest();
-        var query = this.serializeQuery(options.query);
+     sync: function (action, options) {
+        return new Promise(function(resolve, reject){
+            var req = new XMLHttpRequest();
+            var query = this.serializeQuery(options.query);
+
+            req.addEventListener('load', function(){
+                resolve(this.response);
+            }, false);
 
-        req.addEventListener('load', function () {
-            callback(null, req);
-        }, false);
-        req.addEventListener('error', callback, false);
-        req.addEventListener('abort', callback, false);
+            req.addEventListener('error', reject, false);
+            req.addEventListener('abort', reject, false);
 
-        req.open(ACTIONS_TO_METHODS_MAP[action], this.url + (query ? '?' + query : ''), true);
+            req.open(this.ACTIONS_TO_METHODS_MAP[action], this.url + (query ? '?' + query : ''), true);
 
-        req.send(options.body ? JSON.serialize(options.body) : void 0);
+            req.send(options.body ? JSON.serialize(options.body) : void 0);
+        });
     },
 
     /**
-     *
      * @param {String} id
      * @param {Object} value
      * @param {Function} callback
      */
-    create: function (id, value, callback) {
+    create: function (id, value, success, error) {
         this.sync('create', {
             query: {
                 id: id
             },
             body: value
-        }, callback);
+        }).then(function(){
+             success(null);
+        });
     },
 
     /**
@@ -70,12 +140,17 @@ RemoteStorage.prototype = {
      * @param {String} id
      * @param {Function} callback
      */
-    read: function (id, callback) {
+    read: function (id, success, error) {
         this.sync('read', {
             query: {
                 id: id
             }
-        }, callback);
+        }).then(function(value){
+            success(null, value);
+        }).catch(function(){
+            error('Trying to read non existent field')
+        });
+
     },
 
     /**
@@ -84,13 +159,15 @@ RemoteStorage.prototype = {
      * @param {Object} value
      * @param {Function} callback
      */
-    update: function (id, value, callback) {
+    update: function (id, value, success, error) {
         this.sync('update', {
             query: {
                 id: id
             },
             body: value
-        }, callback);
+        }).then(function(){
+             success(null);
+        });
     },
 
     /**
@@ -98,67 +175,20 @@ RemoteStorage.prototype = {
      * @param {String} id
      * @param {Function} callback
      */
-    'delete': function (id, callback) {
+    'delete': function (id, success, error) {
         this.sync('delete', {
             query: {
                 id: id
             }
-        }, callback);
-    }
-};
-
-/**
- *
- * @param {Object} [options]
- * @param {String} [options.storageName='localStorage']
- * @param {String} [options.storagePrefix='']
- * @constructor
- */
-function LocalStorage(options) {
-    options = options || {};
-    this.storageName = options.storageName || 'localStorage';
-    this.storagePrefix = options.storagePrefix || '';
-}
-
-LocalStorage.prototype = Object.assign(Object.create(RemoteStorage.prototype), {
-    /**
-     *
-     * @param {String} id
-     * @param {Object} value
-     * @param {Function} callback
-     */
-    create: function (id, value, callback) {
-        window[this.storageName][this.storagePrefix + id] = JSON.serialize(value);
-        callback(null);
-    },
-
-    /**
-     *
-     * @param {String} id
-     * @param {Function} callback
-     */
-    read: function (id, callback) {
-        callback(null, window[this.storageName][this.storagePrefix + id]);
-    },
-
-    /**
-     *
-     * @param {String} id
-     * @param {Object} value
-     * @param {Function} callback
-     */
-    update: function (id, value, callback) {
-        window[this.storageName][this.storagePrefix + id] = JSON.serialize(value);
-        callback(null);
-    },
-
-    /**
-     *
-     * @param {String} id
-     * @param {Function} callback
-     */
-    'delete': function (id, callback) {
-        callback(null, delete window[this.storageName][this.storagePrefix + id]);
+        }).then(function(response){
+            switch (response) {
+                case 'ok':
+                    success(null, true);
+                    break;
+                case 'not found':
+                    error('Already deleted or not existed');
+                    break;
+            }
+        });
     }
-});
-
+});
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