This module has only one function, which is also exported by default:

subname NAME, CODEREF

Assigns a new name to referenced sub. If package specification is omitted in
the name, then the current package is used. The return value is the sub.

The name is only used for informative routines (caller, Carp, etc). You won't
be able to actually invoke the sub by the given name. To allow that, you need
to do glob-assignment yourself.

Note that for anonymous closures (subs that reference lexicals declared outside
the sub itself) you can name each instance of the closure differently, which
can be very useful for debugging.