require 'MAS::Global';
# or
my $class = 'MAS::Global';
require $class;

##</code><code>##

                    require Foo::Bar;     # a splendid bareword

##</code><code>##

                    my $class = 'Foo::Bar';
                    require $class;       # $class is not a bareword
                #or
                    require "Foo::Bar";   # not a bareword because of the ""

##</code><code>##


                    eval "require $class";