This Metrics::Any adapter type writes observations of metric values into a file. This may be helpful
while debugging or otherwise testing code that reports metrics.
For example, by setting the "METRICS_ANY_ADAPTER" environment variable to configure the adapter, a metric
log will be written as a side-effect of running a unit test:
$ METRICS_ANY_ADAPTER=File:path=metrics.log perl -Mblib t/01test.t
The generated file can then be inspected to see what metric values were reported while the program was
running.
In particular, specifying the file /dev/null allows the full metrics generation path to be tested with
the code under test seeing a "real" adapter even though the output goes nowhere.
$ METRICS_ANY_ADAPTER=File:path=/dev/null ./Build test
Distribution and timing metrics are tracked with a running total and count of observations.
This adapter type does not support batch mode reporting.