code: Filter getFilterProperty(String name, Filter defaultValue) {
          String val = getProperty(name);
          try {
              if (val != null) {
                  return (Filter) getClassInstance(val).newInstance();
              }
          } catch (Exception ex) {
              // We got one of a variety of exceptions in creating the
              // class or creating an instance.
              // Drop through.
          }
          // We got an exception.  Return the defaultValue.
          return defaultValue;
      }
docs: we return the defaultValue.