The JoinRequestQueryBuilder functions enable you to run, sort, filter, and control
which results a query returns.
Typically, you build a query using the queryJoinRequests() function,
refine the query by chaining JoinRequestsQueryBuilder functions, and then execute the
query by chaining the find() function.
For example, the following code returns the first 5 requests to join a group that have been approved, and sorts them by created date in descending order.