docs: void sendEvent(CallEvent call) throws NoConnectionsException, IOException, ProcCallException {
          if (call.endTS == null) {
              assert(call.startTS != null);
              // null callback isn't ideal for production code, but errors are tracked
              // here through client stats so we'll let it slide
              client.callProcedure(new NullCallback(), "BeginCall",
                      call.agentId, call.phoneNoStr(), call.callId, call.startTS);
          }
          else {
              assert(call.startTS == null);
              client.callProcedure(new NullCallback(), "EndCall",
                      call.agentId, call.phoneNoStr(), call.callId, call.endTS);
          }
      }