### Question:
JVMUtils { public static long getUsedMemory() { Runtime runtime = Runtime.getRuntime(); return runtime.totalMemory() - runtime.freeMemory(); } private  JVMUtils(); static void closeAtShutdown(Closeable closeable); static long getUsedMemory();  }### Answer:
@Test public void testUsedMemory() { assertGreaterOrEqual(JVMUtils.getUsedMemory(), 1L << 20); }