code: func (b *BigIP) VirtualServers() (*VirtualServers, error) {
  	var vs VirtualServers
  	err, _ := b.getForEntity(&vs, uriLtm, uriVirtual)
  	if err != nil {
  		return nil, err
  	}
  
  	return &vs, nil
  }
docs: // VirtualServers returns a list of virtual servers.