Instrument for collecting Thread data
Note: This class is a Rakudo-specific feature and not standard Perl 6.
Objects of this class are generally not created by themselves, but rather through making a snapshot.
This class provides the following data points (in alphabetical order):
The number of threads that ended with an exception (threads-aborted).
The number of threads that completed without any problem (threads-completed).
Highest OS thread ID seen (thread-highest-id).
The number of threads that were joined (threads-joined).
The number of threads that were started (threads-started).
The number of times a thread was yielded (threads-yielded).