diff --git a/cyaron/graph.py b/cyaron/graph.py
index 5748acc..66ae82d 100644
--- a/cyaron/graph.py
+++ b/cyaron/graph.py
@@ -46,7 +46,13 @@ def __init__(self, point_count, directed=False):
         """
         self.directed = directed
         self.edges = [[] for i in range(point_count + 1)]
-    
+
+    def vertex_count(self):
+        """edge_count(self) -> int
+            Return the vertex of the edges in the graph.
+        """
+        return len(self.edges) - 1
+
     def edge_count(self):
         """edge_count(self) -> int
             Return the count of the edges in the graph.
diff --git a/cyaron/tests/graph_test.py b/cyaron/tests/graph_test.py
index 1e3f1db..f42959e 100644
--- a/cyaron/tests/graph_test.py
+++ b/cyaron/tests/graph_test.py
@@ -1,3 +1,5 @@
+import itertools
+import random
 import unittest
 from cyaron import Graph
 
@@ -172,3 +174,56 @@ def test_GraphMatrix(self):
         self.assertEqual(str(g.to_matrix(default=9, merge=merge3)), "9 9 3\n9 9 3\n9 1 1")
         self.assertEqual(str(g.to_matrix(default=0, merge=merge4)), "0 0 3\n0 0 1\n0 1 1")
         self.assertEqual(str(g.to_matrix(default=0, merge=merge5)), "0 0 3\n0 0 84\n0 1 1")
+
+    def test_shuffle(self):
+        def read_graph(n, data, directed = False):
+            g = Graph(n, directed)
+            for l in data.split('\n'):
+                u, v, w = map(int, l.split())
+                g.add_edge(u, v, weight=w)
+            return g
+
+        def isomorphic(graph1, graph2, mapping = None, directed = False):
+            n = graph1.vertex_count()
+            if n != graph2.vertex_count():
+                return False
+            if graph1.edge_count() != graph2.edge_count():
+                return False
+            if mapping is None:
+                for per in itertools.permutations(range(1, n + 1)):
+                    if isomorphic(graph1, graph2, (0, ) + per):
+                        return True
+                return False
+            edges = {}
+            for e in graph2.iterate_edges():
+                key, val = (e.start, e.end), e.weight
+                if key in edges:
+                    edges[key].append(val)
+                else:
+                    edges[key] = [val]
+            for e in graph1.iterate_edges():
+                key, val = (mapping[e.start], mapping[e.end]), e.weight
+                if not directed and key[0] > key[1]:
+                    key = key[1], key[0]
+                if key not in edges:
+                    return False
+                if val not in edges[key]:
+                    return False
+                edges[key].remove(val)
+            return True
+
+        def unit_test(n, m, shuffle_kwargs = {}, check_kwargs = {}):
+            g = Graph.graph(n, m)
+            data = g.to_str(**shuffle_kwargs)
+            h = read_graph(n, data)
+            self.assertTrue(isomorphic(g, h, **check_kwargs))
+
+        unit_test(8, 20)
+        unit_test(8, 20, {"shuffle": True})
+        mapping = [0] + random.sample(range(1, 8), k = 7)
+        shuffer = lambda seq: list(map(lambda i: mapping[i], seq))
+        unit_test(7, 10, {"shuffle": True, "node_shuffler": shuffer})
+        unit_test(7, 14, {"shuffle": True, "node_shuffler": shuffer}, {"mapping": mapping})
+        shuffer_without_swap = lambda table: random.sample(table, k=len(table))
+        unit_test(7, 12, {"shuffle": True, "edge_shuffler": shuffer_without_swap}, {"directed": True})
+