Inconsistencies when using random_instance() to generate a random instance of a problem class

[Q-lds]

Problem

When trying to create a random instance of a number partitioning problem, I get the following error

The core issue is that random_instance() is a static method and should be used as such:

The inconsistency is made worst by the fact that I can do the following, where the numbers I pass to the constructor are right away changed by the random_instance() method

#Solution

I am unsure what's the best way to go about this, but we should review the way that random instances are created across the pre-defined problem settings.

[Q-lds]

@vishal-ph and @Adirlou I think we can close this, right?