code: public @Nonnull BugCode getBugCode(String shortBugType) {
          BugCode bugCode = lookupBugCode(shortBugType);
          if (bugCode == null) {
              throw new IllegalArgumentException("Error: missing bug code for key" + shortBugType);
          }
          return bugCode;
      }
docs: Get a description for given "bug type". FIXME: this is referred to
  elsewhere as the "bug code" or "bug abbrev". Should make the terminology
  consistent everywhere. In this case, the bug type refers to the short
  prefix code prepended to the long and short bug messages.
  
  @param shortBugType
  the short bug type code
  @return the description of that short bug type code means