code: function requestCatchup_Dev(oWebSocket, oRequestData) {
  	//
  	//	{ last_stable_mci: last_stable_mci, last_known_mci: last_known_mci }
  	//
  	if (!_bUnitTestEnv) {
  		return console.log(`this function only works in dev env.`);
  	}
  
  	return sendRequest
  	(
  		oWebSocket,
  		'catchup',
  		oRequestData,
  		true,
  		handleCatchupChain
  	);
  }
docs: request catchup in dev
  @param        {object}        oWebSocket
  @param        {object}        oRequestData
  @param        {number}        oRequestData.last_stable_mci
  @param        {number}        oRequestData.last_known_mci
  @return        {*}