code: public List<ResourceGrant> revokeResource(List<Integer> idList) {
      if (deleted) {
        throw new RuntimeException("Session: " +
            sessionId + " has been deleted");
      }
  
      List<ResourceGrant> canceledGrants = new ArrayList<ResourceGrant>();
      for (Integer id : idList) {
        ResourceRequestInfo req = idToRequest.get(id);
        ResourceGrant grant = idToGrant.remove(id);
        if (grant != null) {
  
          if (req == null) {
            throw new RuntimeException("Session: " + sessionId +
                ", requestId: " + id + " grant exists but request doesn't");
          }
  
          removeGrantedRequest(req, true);
  
          // we have previously granted this resource, return to caller
          canceledGrants.add(grant);
        }
      }
      return canceledGrants;
    }
docs: Revoke a list of resources from a session
  @param idList the list of resources to revoke
  @return the list of resource grants that have been revoked