### Question:
SimpleKeyFile implements SecureKeyStore, Configurable, LogSource { @Override public String getRealm () { return realm; } SimpleKeyFile();  SimpleKeyFile(String keyFileName); void init(String keyFileName); @Override void setLogger(Logger logger, String realm); @Override Logger getLogger(); @Override String getRealm(); @Override void setConfiguration(Configuration cfg); @Override synchronized SecureKey getKey(String alias); @Override synchronized void setKey(String alias, SecureKey secureKey); String getProperty(String alias, String subName); void setProperty(String alias, String subName, String value); @Override Map<String, SecureKey> getKeys();  }### Answer:
@Test public void testGetRealm() throws Throwable { String result = new SimpleKeyFile().getRealm(); assertNull(result, "result"); }