How to perform double click on a word within an div element which has long text strings using nightwatch.js

i am testing a web application, i want to perform double click on a word within multiple text strings under an element, for the reference i am attaching an image.

as you can see a highlighted text in a div element, i want to do double click on this word using nightwatch.js.

i tried in following way but it is selecting random word some time "the" sometime to and some time eat from this div element.

client.moveTo('.pf3 div div:nth-child(5)').doubleClick();