func (s *Server) CancelRequest(id string) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.cancel(id) {
		s.log("Cancelled request %s by client order", id)
	}
}
CancelRequest instructs s to cancel the pending or in-flight request with
the specified ID. If no request exists with that ID, this is a no-op.
package jrpc2
import (
	"context"
)
const (
	rpcServerInfo = "rpc.serverInfo"
)