code: public static List<Tag<?>> getCustomTagsFromState(State state) {
      List<Tag<?>> tags = Lists.newArrayList();
      for (String tagKeyValue : state.getPropAsList(METRICS_STATE_CUSTOM_TAGS, "")) {
        Tag<?> tag = Tag.fromString(tagKeyValue);
        if (tag != null) {
          tags.add(tag);
        }
      }
      return tags;
    }
docs: Parse custom {@link org.apache.gobblin.metrics.Tag}s from property {@link #METRICS_STATE_CUSTOM_TAGS}
  in the input {@link org.apache.gobblin.configuration.State}.
  @param state {@link org.apache.gobblin.configuration.State} possibly containing custom tags.
  @return List of {@link org.apache.gobblin.metrics.Tag} parsed from input.