src/main/java/io/github/glytching/junit/extension/system/RestoreContext.java
public void restore() {
    for (String propertyName : propertyNames) {
      if (restoreProperties.containsKey(propertyName)) {
        // reinstate the original value
        System.setProperty(propertyName, restoreProperties.get(propertyName));
      } else {
        // remove the (previously unset) property
        System.clearProperty(propertyName);
      }
    }
  }
public void restore() {
    for (String propertyName : propertyNames) {
      if (restoreProperties.containsKey(propertyName)) {
        // reinstate the original value
        System.setProperty(propertyName, restoreProperties.get(propertyName));
      } else {
        // remove the (previously unset) property
        System.clearProperty(propertyName);
      }
    }
  }
Reverse the system property 'sets' performed on behalf of this restore context.

<p>For each entry in {@link #propertyNames}, if {@link #restoreProperties} contains an entry
then reset the system property with the value from {@link #restoreProperties} otherwise just
remove the system property for that property name.