=begin
1) At ruby-lang.org, under control expressions:
https://docs.ruby-lang.org/en/3.0.0/doc/syntax/control_expressions_rdoc.html#label-while+Loop

2) At ruby-doc.org, under control expressions:
https://ruby-doc.org/core-3.0.2/doc/syntax/control_expressions_rdoc.html#label-while+Loop
=end
