/usr/share/perl5/Mason/Plugin/ is in libmason-perl 2.24-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/Mason/Plugin/Defer/
/usr/share/perl5/Mason/Plugin/Defer.pm
/usr/share/perl5/Mason/Plugin/Defer/Filters.pm
/usr/share/perl5/Mason/Plugin/Defer/Request.pm
/usr/share/perl5/Mason/Plugin/DollarDot/
/usr/share/perl5/Mason/Plugin/DollarDot.pm
/usr/share/perl5/Mason/Plugin/DollarDot/Compilation.pm
/usr/share/perl5/Mason/Plugin/LvalueAttributes/
/usr/share/perl5/Mason/Plugin/LvalueAttributes.pm
/usr/share/perl5/Mason/Plugin/LvalueAttributes/Interp.pm
/usr/share/perl5/Mason/Plugin/TidyObjectFiles/
/usr/share/perl5/Mason/Plugin/TidyObjectFiles.pm
/usr/share/perl5/Mason/Plugin/TidyObjectFiles/Interp.pm
/usr/share/perl5/Mason/PluginBundle/Default.pm