code: public Collection<Request> getRequests(RequestFilter filter, boolean includeSubprojects) {
          filter = (filter != null) ? filter : new RequestFilter();
  
          return getInstance().get().requests(
                  getFilter(filter, includeSubprojects));
      }
docs: Get Requests in this Project filtered as specified in the passed in
  filter.
  
  @param filter             Criteria to filter on. Project will be set automatically.
  If null, all Requests in the project are returned.
  @param includeSubprojects Specifies whether to include items from sub
  project or not. This only adds open sub projects.
  @return A read only Collection of Request.