Description:

require EXPR only accepts Class/Name.pm style module names, not
Class::Name. How frustrating! For that, we provide load_class
'Class::Name'.

It's often useful to test whether a module can be loaded, instead of
throwing an error when it's not available. For that, we provide
try_load_class 'Class::Name'.

Finally, sometimes we need to know whether a particular class has been
loaded. Asking %INC is an option, but that will miss inner packages
and any class for which the filename does not correspond to the
package name. For that, we provide is_class_loaded 'Class::Name'.