code: public List<Integer> hasTag(final Integer tagID) {
          final List<Integer> retValue = new ArrayList<Integer>();
  
          for (final FilterTag tag : getFilterTags()) {
              if (tag.getTag().getTagId().equals(tagID)) retValue.add(tag.getTagState());
          }
  
          return retValue;
      }
docs: Loops through the FilterTags held by this Filter, and returns the state of the tag if it exists, and -1 if it does not.
  
  @param tagID The id of the tag to get the state of
  @return -1 if the tag was not found, otherwise the state of the tag