### Question:
XsuaaServiceConfigurationCustom implements XsuaaServiceConfiguration { @Nullable @Override public String getVerificationKey() { return credentials.getVerificationKey(); } XsuaaServiceConfigurationCustom(XsuaaCredentials credentials); @Override String getClientId(); @Override String getClientSecret(); @Override String getUaaUrl(); @Override String getAppId(); @Override String getUaaDomain(); @Nullable @Override String getVerificationKey();  }### Answer:
@Test public void getVerificationKeyIsNull() { assertNull(cut.getVerificationKey()); }