Test seam: when set, rpc routes the (method, params) pair here and returns the delegate's result payload instead of POSTing to a server, so paginating request methods can be exercised without a live server. Production code never sets this.
Test seam: when set, rpc routes the (method, params) pair here and returns the delegate's result payload instead of POSTing to a server, so paginating request methods can be exercised without a live server. Production code never sets this.