code: private void initEnvironment() {
  		for (Map.Entry<String, String> property : configuration.getEnvProperties().entrySet()) {
  			String name = property.getKey();
  			String newValue = property.getValue();
  
  			String oldValue = getProperty(property.getKey());
  			oldProperties.put(name, oldValue);
  
  			setProperty(name, newValue);
  		}
  	}
docs: Add custom environment properties.
  Initial property value will be store in {@link #oldProperties} map
  and will be restore later.