### Question:
DefaultUserProperties implements UserProperties { @Override public String getLastName() { return (String) getProperty(LAST_NAME); } DefaultUserProperties(ConfigurationSource configurationSource); @Override boolean displayHiddenDocuments(); @Override void setDisplayHiddenDocuments(boolean displayHiddenDocuments); @Override boolean isActive(); @Override void setActive(boolean isActive); @Override String getFirstName(); @Override void setFirstName(String firstName); @Override String getLastName(); @Override void setLastName(String lastName); @Override InternetAddress getEmail(); @Override void setEmail(InternetAddress emailAddress); @Override UserType getType(); @Override void setType(UserType type); @Override Editor getEditor(); @Override void setEditor(Editor editor); @Override boolean isEmailChecked(); @Override void setEmailChecked(boolean isEmailChecked); @Override T getProperty(String key, T defaultValue); @Override T getProperty(String key, Class<T> valueClass); @Override List<String> getKeys(); @Override boolean containsKey(String key); @Override boolean isEmpty(); @Override T getProperty(String key, Class<T> valueClass, T defaultValue); @Override T getProperty(String key); @Override void setProperties(Map<String, Object> properties); @Override void save();  }### Answer:
@Test void getLastName() { when(this.configurationSource.getProperty("last_name")).thenReturn("Doe"); assertEquals("Doe", this.user.getLastName()); }