#vulnerable code 
                                @Test
    public void testCreateEdgeBetweenVertices() {
        Vertex person1 = this.sqlgGraph.addVertex(T.label, "Person");
        Vertex person2 = this.sqlgGraph.addVertex(T.label, "Person");
        this.sqlgGraph.tx().commit();
        person1 = this.sqlgGraph.v(person1.id());
        person2 = this.sqlgGraph.v(person2.id());
        person1.addEdge("friend", person2);
        this.sqlgGraph.tx().commit();
        Assert.assertEquals(1, vertexTraversal(person1).out("friend").count().next().intValue());
        Assert.assertEquals(1, vertexTraversal(person2).in("friend").count().next().intValue());
    } 
                            #location 11 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testCreateEdgeBetweenVertices() {
        Vertex person1 = this.sqlgGraph.addVertex(T.label, "Person");
        Vertex person2 = this.sqlgGraph.addVertex(T.label, "Person");
        this.sqlgGraph.tx().commit();
        person1 = this.sqlgGraph.traversal().V(person1.id()).next();
        person2 = this.sqlgGraph.traversal().V(person2.id()).next();
        person1.addEdge("friend", person2);
        this.sqlgGraph.tx().commit();
        Assert.assertEquals(1, vertexTraversal(person1).out("friend").count().next().intValue());
        Assert.assertEquals(1, vertexTraversal(person2).in("friend").count().next().intValue());
    }