Method modifiers are a powerful feature from the CLOS (Common Lisp Object
System) world.

Class::Method::Modifiers::Fast provides three modifiers: before, around, and
after. before and after are run just before and after the method they modify,
but can not really affect that original method. around is run in place of the
original method, with a hook to easily call that original method. See the
MODIFIERS section for more details on how the particular modifiers work.

Author:
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Takatoshi Kitano