user.runAs(new PrivilegedExceptionAction<Object>() {
public Object run() throws Exception {
// Make sure it worked (above is sensitive to caching details in hadoop core)
FileSystem fs = FileSystem.get(conf);
Assert.assertEquals(FaultyFileSystem.class, fs.getClass());
FaultyFileSystem ffs = (FaultyFileSystem)fs;
HRegion region = null;
try {
// Initialize region
region = initHRegion(tableName, name.getMethodName(), conf, COLUMN_FAMILY_BYTES);
long size = region.getMemstoreSize().get();