chore(modeling): minor SetColorHandler cleanup

lib/features/modeling/cmd/SetColorHandler.js

@@ -3,19 +3,27 @@
 var assign = require('lodash/object/assign'),
     forEach = require('lodash/collection/forEach');
 
+var DEFAULT_COLORS = {
+  fill: undefined,
+  stroke: undefined
+};
+
+
 function SetColorHandler(commandStack) {
   this._commandStack = commandStack;
 }
 
-SetColorHandler.$inject = [ 'commandStack' ];
+SetColorHandler.$inject = [
+  'commandStack'
+];
 
 module.exports = SetColorHandler;
 
 SetColorHandler.prototype.postExecute = function(context) {
   var elements = context.elements,
-      colors = context.colors || { fill: undefined, stroke: undefined };
+      colors = context.colors || DEFAULT_COLORS;
 
-  var that = this;
+  var self = this;
 
   var di = {};
 
@@ -28,7 +36,8 @@ SetColorHandler.prototype.postExecute = function(context) {
   }
 
   forEach(elements, function(element) {
-    that._commandStack.execute('element.updateProperties', {
+
+    self._commandStack.execute('element.updateProperties', {
       element: element,
       properties: {
         di: di
@@ -36,8 +45,4 @@ SetColorHandler.prototype.postExecute = function(context) {
     });
   });
 
-};
-
-SetColorHandler.prototype.execute = function(context) {};
-
-SetColorHandler.prototype.revert = function(context) {};
+};