A tmnxOamTrProbeHistoryEntry is created by the system when the result
of a trace route probe launch is determined.
A tmnxOamTrProbeHistoryEntry is destroyed when the corresponding
tmnxOamTrCtlEntry is destroyed.
The first two indices identify the parent tmnxOamTrCtlEntry. The third
index identifies a trace route test run. Each subsequent index is
described in its DESCRIPTION clause, below.