Drag QDockWidgets between multiple QMainWindows

The docking system in QMainwindow works really well for single monitor solutions but many professional systems today have multiple monitors. Currently it is possible to create multiple mainwindows with their own docks but there's no way to drag a dock from a mainwindow on one monitor to the mainwindow on another monitor. This is a standard feature in most content creation applications such as those from Adobe or Autodesk.