docs: def delete_all_metadata(self):
          """
          ::
          
              DELETE /:login/machines/:id/metadata
          
          :Returns: current metadata
          :rtype: empty :py:class:`dict`
          
          Deletes all the metadata stored for this machine. Also explicitly 
          requests and returns the machine metadata so that the local copy stays 
          synchronized.
          """
          j, r = self.datacenter.request('DELETE', self.path + '/metadata')
          r.raise_for_status()
          return self.get_metadata()