Essay parts
Capture essay entries that are in their own section in a part with role="essay".
//part[@role="essay"]
Example
<mainText>
<part role="essay"><e type="essay" id="acref-9780195123456-e-0358" doi="10.1093/acref/9780195123456.013.0358">
<headwordGroup><!-- Content skipped for brevity --></headwordGroup></e>
</part>
</mainText>