my $old_method;
BEGIN {
    $old_method = CGI->can('header');
};
sub CGI::header {
    print "Before\n";
    $old_method->(@_);
    print "After\n";
};

##</code><code>##

package MyFakeCGI;
use CGI;
sub new {
    my ($class,%options) = @_;
    $options{ cgi } ||= CGI->new;
    my $self = \%options;
    bless $self => $class;
};

sub header {
    my $self = shift;
    print "Before\n";
    $_[0]->{cgi}->header->(@_);
    print "After\n";
};

# Delegate everything else to CGI
sub AUTOLOAD {
    goto &CGI::AUTOLOAD;
};

# Don't delegate DESTROY
sub DESTROY {};

1;