code: function buildMessageBuilder(section) {
  
  	const logOptions = process.env.X2_LOG || '';
  
  	const msgBuilder = new Array();
  
  	if (!/(^|,)nots(,|$)/i.test(logOptions))
  		msgBuilder.push(() => (new Date()).toISOString());
  
  	if (!/(^|,)nopid(,|$)/i.test(logOptions))
  		msgBuilder.push(() => String(process.pid));
  
  	let m;
  	const envRE = new RegExp('(?:^|,)env:([^,]+)', 'gi');
  	while ((m = envRE.exec(logOptions)) !== null) {
  		const envName = m[1];
  		msgBuilder.push(() => process.env[envName]);
  	}
  
  	if (section && !/(^|,)nosec(,|$)/i.test(logOptions))
  		msgBuilder.push(() => section);
  
  	return msgBuilder;
  }
docs: Build message build functions list.
  
  @private
  @param {string} [section] Debug log section, nothing if error log.
  @returns {Array.<function>} Message builder functions.