$usage->die unless GetOptions(\%return, grep { length } @specs);

##</code><code>##

  my $usage = bless sub {
    my ($as_string) = @_;
    ...
    return $buffer if $as_string;
  } => "Getopt::Long::Descriptive::Usage";

##</code><code>##

sub die  { 
  my $self = shift;
  my $arg  = shift || {};

  die(
    join(
      "", 
      grep { defined } $arg->{pre_text}, $self->text, $arg->{post_text},
    )
  );
}

##</code><code>##

sub text { shift->(1) }