diff --git a/tests/functionalty.spec.ts b/tests/functionalty.spec.ts
index 36324cf..848d9d2 100644
--- a/tests/functionalty.spec.ts
+++ b/tests/functionalty.spec.ts
@@ -5,7 +5,8 @@ import { MaxHeap, MinHeap } from '../src/index';
 
 describe('Functionality', () => {
   it('it works as a max heap', () => {
-    const maxHeap = new MaxHeap((x) => x, [1, 7, 5, 8].values());
+    const maxHeap = new MaxHeap((x) => x);
+    maxHeap.insertMany([1, 7, 5, 8].values());
 
     const sortedArray = [];
 
@@ -20,7 +21,8 @@ describe('Functionality', () => {
   });
 
   it('it works as a min heap', () => {
-    const minHeap = new MinHeap((x) => x, [1, 7, 5, 8].values());
+    const minHeap = new MinHeap((x) => x);
+    minHeap.insertMany([1, 7, 5, 8].values());
 
     const sortedArray = [];
 
@@ -35,7 +37,8 @@ describe('Functionality', () => {
   });
 
   it('it works with sets', () => {
-    const maxHeap = new MaxHeap((x) => x, new Set([1, 7, 5, 8]).values());
+    const maxHeap = new MaxHeap((x) => x);
+    maxHeap.insertMany([1, 7, 5, 8].values());
 
     const sortedArray = [];
 
@@ -57,7 +60,8 @@ describe('Functionality', () => {
     map.set(5, '5');
     map.set(8, '8');
 
-    const maxHeap = new MaxHeap((x) => x, map.keys());
+    const maxHeap = new MaxHeap((x) => x);
+    maxHeap.insertMany(map.keys());
 
     const sortedArray = [];
 
@@ -74,10 +78,8 @@ describe('Functionality', () => {
   it('it works with complex objects given the right extractor', () => {
     const array = [{ id: 1 }, { id: 7 }, { id: 3 }, { id: 8 }];
 
-    const maxHeap = new MaxHeap(
-      (x) => x.id,
-      array.values(),
-    );
+    const maxHeap = new MaxHeap((x:{id:number}) => x.id);
+    maxHeap.insertMany(array.values());
 
     const sortedArray = [];
 
@@ -94,7 +96,8 @@ describe('Functionality', () => {
   it('it works with complex objects given the right extractor and use insert many for bulk', () => {
     const array = [{ id: 1 }, { id: 7 }, { id: 3 }, { id: 8 }];
 
-    const maxHeap = new MaxHeap((x) => x.id, array.values());
+    const maxHeap = new MaxHeap((x:{id:number}) => x.id);
+    maxHeap.insertMany(array.values());
 
     const newArray = [{ id: 2 }];
     const sortedArray = [];