    # File lib/fog/openstack/requests/compute/list_security_groups.rb, line 6
            def list_security_groups(server_id = nil)
              path = "os-security-groups.json"
              if server_id
                path = "servers/#{server_id}/#{path}"
              end
              request(
                :expects  => [200],
                :method   => 'GET',
                :path     => path
              )
            end