code: static String typeVarToString(DocEnv env, TypeVar v, boolean full) {
          StringBuilder s = new StringBuilder(v.toString());
          List<Type> bounds = getBounds(v, env);
          if (bounds.nonEmpty()) {
              boolean first = true;
              for (Type b : bounds) {
                  s.append(first ? " extends " : " & ");
                  s.append(TypeMaker.getTypeString(env, b, full));
                  first = false;
              }
          }
          return s.toString();
      }
docs: Return the string form of a type variable along with any
  "extends" clause.  Class names are qualified if "full" is true.