Sample
data class Sample(val exitCode: Int, val wallMs: Long, val userMs: Long? = null, val systemMs: Long? = null, val peakKb: Long? = null, val cgroup: CgroupDelta? = null)(source)
One recorded execution of a command. userMs, systemMs, peakKb and cgroup are null when the host could not measure them; the JSON leaves the key out, so absent never reads as zero.