Returns true if a BreakdownSet contains no entries. If there are any Breakdowns in the set even if they contain no values this function will return false. This is a useful function when developing new KPI formula as it can be used for simple debug logging.
var issues = metrics.get('critical issues').getLatest();
if (issues.breakdown().isEmpty()){
console.log('No breakdown data for critical issues for date: %s',
now);
}