I need to append a value (like an id) to all requests of a project, so I add it at the request interceptor. I do not want to lose all other parameters, with this line of code at interceptor:

request = request.clone({
    body: {...request.body, project: projectId}
});

if the parameters are of type FormData I face problem cause I should append the value to FormData but How can I make difference between FormData and simple object body.