How to write unit test in Angular for a response that is coming from API

Question

I have got the below function where the response is coming from an API call.

private getDetails(searchedID) {
    this.entityService.getDetailsById(searchedID).subscribe(
        response => {
            this.searchedDetail = response;
            this.setEntityDetails(this.searchedDetails);

        },
        (error) => {

            if (error.error instanceof Error) {
                const errMessage = error.error.message;
                this.logger.logError('Message -' + errMessage);
            }
            this.messages.displayResponseMessage("Error getting entity details", 3000, "snackbar-error");
        });
}

Can someone give me suggestions on how to achieve unit test coverage for the 'response' block?