I am trying to copy a dashboard object from one workspace to another using API. 

I am using Get dashboard objects (/api/2.0/preview/sql/dashboards GET method), then Retrieve a definition (/api/2.0/preview/sql/dashboards/{dashboard_id} GET method) and after retrieving a definition. Until this step, everything seems fine, but the last step in my opinion is somehow broken. I am trying to restore the dashboard using Create a dashboard object (/api/2.0/preview/sql/dashboards POST method). The engine will return 200 and the object created but the widgets are equal to None, so the object is created and visible on Dashboards screen but in fact, it is quite empty. 

Can you help me?