Where is my test helper for ember-power-select?

I am reading the docs for ember-power-select testings here.

On the setup, it says:

import registerPowerSelectHelpers from '../../tests/helpers/ember-power-select';

registerPowerSelectHelpers();
...

I do not see ember-power-select in my tests/helpers/ directory. Am I supposed to install it separately, or was it supposed to come by default?

I installed ember-power-select by running the command suggested: ember install ember-power-select.

How can I use some of the power-select helpers like selectChoose(), selectSearch(), &c. like prescribed on the docs?