code: public function it_updates_an_existing_pipeline_by_attaching_and_detaching_pipes($parser, $files)
      {
          $updated = ['RegisterUser' => ['Logger', 'Buzzer']];
  
          $parser->dump($updated)->willReturn('foo');
  
          $files->put('path/to/workflows/workflows.yml', 'foo')->shouldBeCalled();
  
          $this->update('RegisterUser', ['Buzzer'], ['Notifier']);
      }
docs: @testdox    It updates an existing pipeline by attaching and detaching pipes.
  
  @author    Andrea Marco Sartori
  @return    void