code: func (m *DatastoreFileManager) DeleteVirtualDisk(ctx context.Context, name string) error {
  	p := m.Path(name)
  
  	var merr error
  
  	if m.Force {
  		merr = m.markDiskAsDeletable(ctx, p)
  	}
  
  	task, err := m.VirtualDiskManager.DeleteVirtualDisk(ctx, p.String(), m.Datacenter)
  	if err != nil {
  		log.Printf("markDiskAsDeletable(%s): %s", p, merr)
  		return err
  	}
  
  	return m.wait(ctx, task)
  }
docs: // DeleteVirtualDisk calls VirtualDiskManager.DeleteVirtualDisk
  // Regardless of the Datastore type, DeleteVirtualDisk will fail if 'ddb.deletable=false',
  // so if Force=true this method attempts to set 'ddb.deletable=true' before starting the delete task.