You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: resource_response_middleware_test.go
    path of file: ./repos/grafana/pkg/services/pluginsintegration/clientmiddleware
    
    the code of the file until where you have to start completion: package clientmiddleware

import (
	"context"
	"net/http"
	"testing"

	"github.com/grafana/grafana-plugin-sdk-go/backend"
	"github.com/grafana/grafana/pkg/plugins/manager/client/clienttest"
	"github.com/stretchr/testify/require"
)

func TestResourceResponseMiddleware(t *testing.T) {
	t.Run("Should set proxy response headers when calling CallResource", func(t *testing.T) {
		crResp := &backend.CallResource
    
func TestResourceResponseMiddleware(t *testing.T) {
	t.Run("Should set proxy response headers when calling CallResource", func(t *testing.T) {
		crResp := &backend.CallResourceResponse{
			Status: http.StatusOK,
			Headers: map[string][]string{
				"X-Custom": {"Should not be deleted"},
			},
		}
		cdt := clienttest.NewClientDecoratorTest(t,
			clienttest.WithMiddlewares(NewResourceResponseMiddleware()),
			clienttest.WithResourceResponses([]*backend.CallResourceResponse{crResp}),
		)

		var sentResponse *backend.CallResourceResponse
		sender := callResourceResponseSenderFunc(func(res *backend.CallResourceResponse) error {
			sentResponse = res
			return nil
		})

		err := cdt.Decorator.CallResource(context.Background(), &backend.CallResourceRequest{
			PluginContext: backend.PluginContext{},
		}, sender)
		require.NoError(t, err)

		require.NotNil(t, sentResponse)
		require.Equal(t, "sandbox", sentResponse.Headers["Content-Security-Policy"][0])
		require.Equal(t, "Should not be deleted", sentResponse.Headers["X-Custom"][0])
	})
}