code: public static Class<? extends Tag> getClassFor(int id) {
          if(!idToTag.containsKey(id)) {
              return null;
          }
  
          return idToTag.get(id);
      }
docs: Gets the tag class with the given id.
  
  @param id Id of the tag.
  @return The tag class with the given id, or null if it cannot be found.