code: def login
        params = {
          'method' => :post,
          'command' => '/sessions'
        }
  
        response, headers = send_request(params)
  
        if !headers.has_key?(:x_vcloud_authorization)
          raise "Unable to authenticate: missing x_vcloud_authorization header"
        end
  
        extensibility_link = response.css("Link[rel='down:extensibility']")
        @extensibility = extensibility_link.first['href'] unless extensibility_link.empty?
  
        @auth_key = headers[:x_vcloud_authorization]
      end
docs: Authenticate against the specified server