private void appendTyparamString(TypeVar t, StringBuilder buf) {
            buf.append(t);
            if (t.bound == null ||
                t.bound.tsym.getQualifiedName() == names.java_lang_Object)
                return;
            buf.append(" extends "); // Java syntax; no need for i18n
            Type bound = t.bound;
            if (!bound.isCompound()) {
                buf.append(bound);
            } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
                buf.append(supertype(t));
                for (Type intf : interfaces(t)) {
                    buf.append('&');
                    buf.append(intf);
                }
            } else {
                // No superclass was given in bounds.
                // In this case, supertype is Object, erasure is first interface.
                boolean first = true;
                for (Type intf : interfaces(t)) {
                    if (!first) buf.append('&');
                    first = false;
                    buf.append(intf);
                }
            }
        }