[Tex/LaTex] How display marginal labels on bibliography entries with showlabels

Question

How can I cause marginal labels to appear for entries in the printed bibliography if I am using the showlabels package? (Note that I mean labels in the margin rather than the numbers or names, etc., that are printed within the bibliography.)

(I'm not asking about causing labels to appear where \cite commands appear in the text.)

With the showkeys package instead of showlabels, they appear automatically.

ADDED

If I merely load the showlabels package and include a \showlabels{bibitem}, that will not produce labels for the actual items in the References section (although it will produce labels at the various \cite locations). For example:

\documentclass[12pt]{article}

\begin{filecontents}{short.bib}
@book{Doe2016,
  author = {Doe, Jane},
  title = {Theory of everything},
  publisher = {YourBooks},
  year = {2016}
}
\end{filecontents}

\usepackage[backend=bibtex]{biblatex}
\usepackage[names,dvipsnames,named]{xcolor}
\usepackage[colorlinks,linkcolor=blue]{hyperref}

\usepackage{showlabels}
\renewcommand{\showlabelfont}{\small\color{blue}}
\showlabels[\small\color{gray}]{cite}
\showlabels[\small\color{red}]{bibitem}

\addbibresource{short}

\begin{document}

\section{A section}\label{sec:one}

Look at Section~\ref{sec:one} for more information. Read more about it in Doe~\cite{Doe2016}. 

\printbibliography

\end{document}

Output:

Answer 1

The package author, Norman Gray, provided a solution:

\makeatletter
\showlabels{blx@bibitem}
\makeatother