@Test
    public void testToMassesCsvOnTwoConnectedMasses() {
        graph.addMasses(mass1, mass2);
        graph.addSpring(mass1, mass2);

        result = GraphConverter.toMassesCsv(graph);
        assertEquals(MASSES_PREAMBLE
                + "t,5.0,6.0,0\n"
                + "t,11.0,12.0,0,0\n", result);
    }