Provided by: perl-doc_5.22.1-9ubuntu0.9_all 

NAME
ExtUtils::MY - ExtUtils::MakeMaker subclass for customization
SYNOPSIS
# in your Makefile.PL
sub MY::whatever {
...
}
DESCRIPTION
FOR INTERNAL USE ONLY
ExtUtils::MY is a subclass of ExtUtils::MM. Its provided in your Makefile.PL for you to add and override
MakeMaker functionality.
It also provides a convenient alias via the MY class.
ExtUtils::MY might turn out to be a temporary solution, but MY won't go away.
perl v5.22.1 2020-10-19 ExtUtils::MY(3perl)