Service Fabric - Calling one controller from another (REST API)

Here's some code to show how it's done:

[Route("api/[controller]")]

[ApiController]

public class MySecondController : ControllerBase

{

   [HttpPut("{param}")]

   public ActionResult<string> Update([FromRoute]string param)

   {

      // do some important work...

      // call the First Controller

      var ctrl = new MyFirstController();
      ctrl.ControllerContext = ControllerContext;
      return ctrl.Get(parm);