Thicker hrulefill in res class

Question

How do I make a thicker horizontal line using hrulefill in res class? I have the following in my preamble. Is it possible to modify it in some way to reflect the change?

\newcommand{\fullhrulefill}
{
    \hspace*{-\sectionwidth}
    \hrulefill
}

Answer 1

Borrowing from David's answer at What is the thickness of \hrulefill, except here, I don't redefine \hrulefill, but rather replace its use inside of \fullhrulefill.

\documentclass{res}
\makeatletter
\newcommand{\fullhrulefill}
{%
    \def\xhrulefill{\leavevmode\leaders\hrule height 2pt\hfill\kern\z@}%
    \hspace*{-\sectionwidth}%
    \xhrulefill%
}
\makeatother
\begin{document}
\fullhrulefill

\noindent\hrulefill
\end{document}