code: public static <S extends Enum<S>> S getSystemPropertyAsEnum(Class<S> type, String name) {
          return getSystemPropertyAsEnum(type, name, null);
      }
docs: Replies the value of the enumeration system property.
  
  @param <S>
  - type of the enumeration to read.
  @param type
  - type of the enumeration.
  @param name
  - name of the property.
  @return the value, or <code>null</code> if no property found.