Tutorials: https://developers.sap.com/tutorials/odata-06-extend-odata-service.html
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When I reach the last step of that tutorial : https://developers.sap.com/tutorials/odata-07-extend-custom-code.html
Multiple error prevent to properly load some CSS and javascript files of the web page. (I am talking about the code of the page not the content of the tutorial.) It's then impossible to continue, read the content and finish the last step of the Mission :/