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: fcm_test.go
    path of file: ./repos/uniqush-push/srv
    
    the code of the file until where you have to start completion: package srv

import (
	"testing"
)
import (
	"github.com/uniqush/uniqush-push/push"
)

func testToFCMPayload(t *testing.T, postData map[string
    
func TestToFCMPayloadWithCommonParameters(t *testing.T) {
	postData := map[string]string{
		"msggroup":  "somegroup",
		"other":     "value",
		"other.foo": "bar",
		"ttl":       "5",
		// FCM module should ignore anything it doesn't recognize beginning with "uniqush.", those are reserved.
		"uniqush.payload.apns": "{}",
		"uniqush.foo":          "foo",
	}
	regIds := []string{"CAFE1-FF", "42-607"}
	expectedPayload := `{"registration_ids":["CAFE1-FF","42-607"],"collapse_key":"somegroup","time_to_live":5,"data":{"other":"value","other.foo":"bar"}}`
	testToFCMPayload(t, postData, regIds, expectedPayload)
}