Subfigures should be converted to *fig-group* elements.

```
% pandoc -f latex -t jats
\begin{figure}[H]
  \begin{subfigure}
    \centering
    \includegraphics[height=1.5in]{assets/A.png}
    \caption{Graph for function *A*.}
    \label{fig:A}
  \end{subfigure}
  \begin{subfigure}
    \centering
    \includegraphics[height=1.5in]{assets/B.png}
    \caption{Graph for function *B*.}
    \label{fig:B}
  \end{subfigure}
  \label{fig:graphs}
  \caption{Function graphs.}
\end{figure}
^D
<fig-group id="figU003Agraphs">
  <caption><p>Function graphs.</p></caption>
  <fig id="figU003AA">
    <caption><p>Graph for function *A*.</p></caption>
    <graphic mimetype="image" mime-subtype="png" xlink:href="assets/A.png" />
  </fig>
  <fig id="figU003AB">
    <caption><p>Graph for function *B*.</p></caption>
    <graphic mimetype="image" mime-subtype="png" xlink:href="assets/B.png" />
  </fig>
</fig-group>
```