fix(front, back) -> undefined exception; feat(resize)

src/List.js

@@ -35,6 +35,16 @@ export class List {
     return this._end.clone()
   }
 
+  resize(size, value) {
+    if (this._size > size)
+      while (this._size !== size)
+        this.popBack()
+
+    else
+      while (this._size !== size)
+        this.pushBack(value)
+  }
+
   _shiftRight(dest, generator) {
     let prev, res, new_item, item = dest.deref()
 
@@ -75,7 +85,7 @@ export class List {
   }
 }
 
-List.from = function (obj) {
+List.from = function(obj) {
   const list = new List()
   for (const value of obj) {
     list.pushBack(value)
@@ -98,6 +108,7 @@ export class ListItem {
 }
 
 export class ListIterator {
+
   constructor(item) {
     this._item = item
   }
@@ -130,4 +141,4 @@ export class ListIterator {
   }
 }
 
-mixinClasses(ListIterator, BidirectionalIterator)
+mixinClasses(ListIterator, BidirectionalIterator)