code: private static Integer getLogLevel(String tag) {
          Integer result = logLevels.get(tag);
          if (tag != null && result == null) {
              int index = tag.lastIndexOf(".");
              while (result == null && index > -1) {
                  result = logLevels.get(tag.substring(0, index));
                  index = tag.lastIndexOf(".", index - 1);
              }
          }
          return result;
      }
docs: If called with "a.b.c.d", it will test for a.b.c.d, a.b.c, a.b, a