title: React material UI accordion: how to call a function when accordion is open?
body: <p>I'm using React material-ui.
  I'm trying to call a function only when the <code>Accordion</code> is open:</p>
  <pre><code>                                &lt;Accordion  opened={()=&gt;this.myFn(row.id)} &gt;
                                  &lt;AccordionSummary
  
                                      expandIcon={&lt;ExpandMoreIcon/&gt;}
                                      aria-controls=&quot;panel1a-content&quot;
                                      id={row.id}
  
                                  &gt;
                                      &lt;Typography&gt;{row.name}&lt;/Typography&gt;
                                  &lt;/AccordionSummary&gt;
                                  &lt;AccordionDetails id={row.id} &gt;
  
                                     &lt;p&gt;something &lt;p/&gt;
  
                                  &lt;/AccordionDetails&gt;
                              &lt;/Accordion&gt;
  </code></pre>