Get users with specific fields

I’m using management api to fetch users by calling auth0client.getUsers({ fields: string}).
And to fetch the users with specific fields there only a string value should be passed to fields param, however when I want to pass multiple fields there is no clear way how these fields should be passed since it’s only a string value.
is it a comma separated string? semi-colon separated? didn’t work. also it’s not clear in the api documentation.

just figured it out, it should be comma separated like this : fields: email,user_id without any spaces.
but it would be nice if it’s been already cleared in the docs.