Protractor File Upload using button

Can someone post an example of how to upload a file in protractor using a button? Not sure if setFileDetector is needed in here or not.

I am using Protractor, JS, selenium standalone server, and have a button to select a file, i.e.

Button: Select File

button id="upload-button" class="button" ng-file-select ng-file-change="uploadCtrl.upload($files)" ng-accept="'*.jpg, *.gif'"

Can someone explain how to upload the file in protractor? Thanks!!