Description:

The UNIVERSAL class provides a few default methods so that all objects
can use them. Object orientation allows programmers to override these
methods in subclasses to provide more specific and appropriate
behavior.

Some authors call methods in the UNIVERSAL class on potential
invocants as functions, bypassing any possible overriding. This is
wrong and you should not do it. Unfortunately, not everyone heeds this
warning and their bad code can break your good code.

Fortunately, this module replaces UNIVERSAL::can() with a method that
checks to see if the first argument is a valid invocant (whether an
object - a blessed referent - or the name of a class). If so, and if
the invocant's class has its own can() method, it calls that as a
method. Otherwise, everything works as you might expect.

If someone attempts to call UNIVERSAL::can() as a function, this
module will emit a lexical warning (see perllexwarn) to that effect.
You can disable it with no warnings; or no warnings 'UNIVERSAL::isa';,
but don't do that; fix the code instead.