Controller.scala" class="shortcut"><code>ApiController</code></a> defines the following method
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<pre><code>processSortByParam(sortBy: Option[String], allowedFields: Seq[String], default: String): Either[ApiError, Seq[(String, Boolean)]]</pre></code>
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				It takes the <code>sort</code> parameter, a list of available allowed fields to sort by, and a default sorting string. Then it returns a list of pairs <code>(String, Boolean)</code> with the corresponding field and order (true if it's descenden