code: private void destroyEnvironment() {
  		for (Map.Entry<String, String> property : configuration.getEnvProperties().entrySet()) {
  			String name = property.getKey();
  
  			String oldValue = oldProperties.get(name);
  			oldProperties.remove(name);
  
  			if (oldValue == null) {
  				clearProperty(name);
  			}
  			else {
  				setProperty(name, oldValue);
  			}
  		}
  	}
docs: Reset custom environment properties.
  Initial values stored in {@link #oldProperties} will be restored
  or clear.