code blocks not rendering correctly

<br />
<code></code><code></code>java
    class MyIndex implements Supplier<Integer> {
        int index = 0;
        @Override
        public void get() {
            return index++;
        }
    }
<code></code>

renders as the following:

<br />
<pre class="wp-code-highlight prettyprint linenums:1"><code class="java">    class MyIndex implements Supplier<Integer> {<br />
        int index = 0;<br />
        @Override<br />
        public int get() {<br />
            return index++;<br />
        }<br />
    }<br />

which causes the <code class=’java’> to be displayed to the user which is undesirable.

I realize this is part of Markdown Extra, but is there anything I can do here? N.B. if I take off the triple quote java and closing triple quote characters and just leave the code indented by 4 spaces (ie normal Markdown), the only difference is the <code> tag does not include the class attribute.

** due to formatting problems here, please see this gist: https://gist.github.com/jeffbowman/5d96ad6a98576036bfea

https://wordpress.org/plugins/jetpack-markdown/