code: public boolean registerBugCategory(BugCategory bc) {
          String category = bc.getCategory();
          if (categoryDescriptionMap.get(category) != null) {
              return false;
          }
          categoryDescriptionMap.put(category, bc);
          return true;
      }
docs: Set the metadata for a bug category. If the category's metadata has
  already been set, this does nothing.
  @param bc
  the BugCategory object holding the metadata for the category
  
  @return false if the category's metadata has already been set, true
  otherwise