clean code

lib/models/user-group-relation.js

@@ -66,8 +66,6 @@ class UserGroupRelation {
    */
   static findAllRelationForUserGroup(userGroup) {
     debug('findAllRelationForUserGroup is called', userGroup);
-    var UserGroupRelation = this;
-
     return this
       .find({ relatedGroup: userGroup })
       .populate('relatedUser')
@@ -83,7 +81,6 @@ class UserGroupRelation {
    * @memberof UserGroupRelation
    */
   static findAllRelationForUserGroups(userGroups) {
-
     return this
       .find({ relatedGroup: { $in: userGroups } })
       .populate('relatedUser')
@@ -99,7 +96,6 @@ class UserGroupRelation {
    * @memberof UserGroupRelation
    */
   static findAllRelationForUser(user) {
-
     return this
       .find({ relatedUser: user.id })
       .populate('relatedGroup')
@@ -199,10 +195,6 @@ class UserGroupRelation {
       .then((count) => {
         // return true or false of the relation is exists(not count)
         return (0 < count);
-      })
-      .catch((err) => {
-        debug('An Error occured.', err);
-        reject(err);
       });
   }
 
@@ -263,10 +255,6 @@ class UserGroupRelation {
         else {
           relationData.remove();
         }
-      })
-      .catch((err) => {
-        debug('Error on find a removing user-group-relation', err);
-        reject(err);
       });
   }