package DEBUG;
use strict;
sub import
{
    my $pkg= shift @_;
    my $default= 1;
    if(  @_  &&  'inherit' eq $_[0]  ) {
        return
            if  defined \&::DEBUG;
        shift @_;
        $default= 0;
    }
    if(  @_  &&  $_[0] =~ /^(on|off)$/  ) {
        $default= 'on' eq $_[0] ? 1 : 0;
        shift @_;
    }
    if(  @_  ) {
        require Carp;
        Carp::croak( "Usage: use DEBUG ['inherit',] ['on'|'off'];" );
    }
    eval "sub ::DEBUG() { $default; }; 1"
        or  die $@;
}
sub unimport
{
    if(  2 < @_  ||  2 == @_ && 'inherit' ne $_[1]  ) {
        require Carp;
        Carp::croak( "Usage: no DEBUG ['inherit'];" );
    }
    import(@_,'off');
}