Look at the stars for a while.
xtrapoletariat
The sequel's plot is somehow weak with a couple of cringe moments. Given the twist is revealed in part one, the movie expresses one of many solutions to what should be free roaming of your own thoughts after the first film.
Sequels can be awful at destroying the 'blew my mind' effect in general by streamlining a great, open idea to a specific plot I guess.
Apologies for being too cryptic/jargon. Pro tip: a real-life mentor can adapt to your level on-the-fly, if available.
Maybe this introduction helps a bit to get an overview - from the context I expect you are on JavaScript or related.
It's often hard to grasp why packages or techniques exist unless you ran into the problems that motivated the solution yourself.
In this case, it's all about filtering by the severity of log messages (debug level). If the level is high, your app will show tiny bits of information. These do not need to show for every user, except if they want to enable it (via techniques like a switch/flag, environment variable or a config file).
Config files or profiles are often used to enable/disable code parts in production or to configure how often scheduled jobs should be triggered and so on.
Depending on your level of expertise logging stuff via the console may be just fine for the moment. In particular if you are the sole developer. Once you're annoyed by your own logs, incrementally replace the 'prints' with a library that feels comfortable or well-documented.
The question mixes up tests and logging. You are referring to logs.
Use a good logging package. It will allow you to distinguish at least (possibly with verbosity levels)
- trace
- debug
- information
- warning
- error
In production, configure the log level to be info-level or above, everything below will be hidden.
Lower levels can be useful for debugging automated tests. Possibly via a flag in production as well.
There were several incidents (ref. 1), but in particular Fukushima in 2011 changed a lot, as it was a modern type of power plant.
It reignited discussions regarding safety and (under the impression of 9/11) fears that nuclear power facilities could be targeted by terror attacks.
With current regulations new reactors can cost some 20 to 40 billion, making it one of the most expensive sources of electrical energy. Costs for decomissioning are significant as well. Both building and decomissioning costs are typically passed on to tax payers.
Also, permanent storage of used burning rods is hard, nobody wants nuclear waste buried in their neighborhood. Given its half life of ~240 000 years, it may also be difficult to communicate its dangers to future generations (ref. 2).
The currently most common sources of burning material (Uranium) stem from - large parts - politically controverse regions and may in sum last some estimated 80-100 years, quite short given some 10-20 years of construction time per plant.
This is not talking about thorium and salt reactors, but technical challenges and costs seem to be limiting for these technologies, in particular as long as the default infrastructure exists.
edit: the 'new' types are more complex and not suited for weapons in general.
1: https://en.wikipedia.org/wiki/List_of_civilian_nuclear_accidents?wprov=sfla1
2: https://www.youtube.com/watch?v=PUXwrWMS-x8