### Question:
InstrumentedClassState { public void update(final String installableId, final byte[] classBytes) { this.classBytes = classBytes; this.installableIds.add(installableId); } InstrumentedClassState(final String installableId, final byte[] classBytes); void update(final String installableId, final byte[] classBytes);  }### Answer:
@Test public void testUpdateWorks(){ InstrumentedClassState data = new InstrumentedClassState(INSTALLABLE_ID_1, INITIAL); data.update(INSTALLABLE_ID_2, UPDATED); Assert.assertTrue(data.getClassBytes().equals(UPDATED)); Assert.assertTrue(data.getInstallableIds().contains(INSTALLABLE_ID_1)); Assert.assertTrue(data.getInstallableIds().contains(INSTALLABLE_ID_2)); }