def create_collection(self):
        collection = CPolylineCollection()
        p1 = CPolyline( name = "POLY1" , init_points = [(0,10) , (1,11) , (2,12)])
        p2 = CPolyline( name = "POLY2" , init_points = [(0,100) , (10,110) , (20,120)])
        collection.addPolyline( p1 )
        collection.addPolyline( p2 )

        tail  = p1[-1]
        self.assertEqual( tail , (2,12))
        self.assertEqual(p1.getName() , "POLY1")
        
        tail  = p2[-1]
        self.assertEqual( tail , (20,120))
        self.assertEqual(p2.getName() , "POLY2")
        
        return collection
    def test_add_polyline(self):
        pc = CPolylineCollection()
        pl = pc.createPolyline( name = "TestP" )
        self.assertTrue( isinstance(pl , CPolyline))
        self.assertEqual(len(pc) , 1)
        self.assertTrue( "TestP" in pc )
        
        with self.assertRaises(IndexError):
            pl = pc[2]

        p0 = pc[0]
        self.assertTrue( p0 == pl )
            
        with self.assertRaises(KeyError):
            pn = pc["missing"]
            
        pn = pc["TestP"]
        self.assertTrue( pn == pl )

        px = CPolyline( name = "TestP")
        with self.assertRaises(KeyError):
            pc.addPolyline( px )
        self.assertEqual(len(pc) , 1)
            

        p2 = CPolyline( name = "Poly2")
        pc.addPolyline( p2 )
        
        self.assertEqual( len(pc) , 2 )
        self.assertTrue( "Poly2" in pc )

        l = []
        for p in pc:
            l.append(p)
        self.assertEqual( len(pc) , 2 )


        points = [(0,1) , (1,1)]
        pc.addPolyline( points , name = "XYZ")
        self.assertTrue( "XYZ" in pc )