XCTest overriding defaultMetrics not working for me.

I'm trying to get a handle on XCTest performance measurement, but they don't seem to work the way I understand them (which is very possibly incorrect).

There are:

defaultMetrics: [XCTMetric]

XCTestCase

- which includes:

XCTClockMetric, XCTCPUMetric, XCTMemoryMetric, et al.

and:

defaultPerformanceMetrics: [XCTPerformanceMetric]

XCTestCase

measure(_:)

- which includes the sole:

wallClockTime: XCTPerformanceMetric

If I override:

    override class var defaultMetrics: [XCTMetric] {

        return [XCTMemoryMetric(), XCTCPUMetric(), XCTClockMetric()]
    }

and call:

self.measure(work)

All I see in the report is Duration and Time.

Yet if I pass an array of metrics in,

self.measure(metrics: [XCTMemoryMetric(), XCTCPUMetric(), XCTClockMetric()], block: work)

it works and displays CPU Cycles and Memory Physical etc.

Shouldn't the measure() method use the defaults I've specified?

Also, if I've overridden defaultPerformaceMetrics(), those metrics are only displayed if I don't pass XCTMetrics to measure(metrics:).

Ultimately, what I want is a report that displays the XCTMetrics I specify as well as the XCTPerformanceMetrics. I know there are other perf metrics beyond just wallClockTime.