Class: Rindow\RL\Agents\Util\ProgressBar
start($title,$numIterations,$maxDot) initializes timing and prints an empty
bar. update($iteration) redraws elapsed and estimated remaining time.
clearProgressBar() temporarily removes it before a log line, and
retrieveProgressBar() redraws the previous state.
laptime() returns elapsed seconds; laptimeString() returns MM:SS or
H:MM:SS. Subclasses may override the protected console() method to redirect
output; the default destination is STDERR.