use strict; 
 
sub trace_wrapper_no_frame { 
    my $f=shift; 
    return sub { 
        print "Trace, no frame\n"; 
        goto $f; 
    }; 
} 
 
sub trace_wrapper_frame { 
    my $f=shift; 
    return sub { 
        print "Trace, with frame\n"; 
        $f->(@_); # <----- LINE 15 
    }; 
 
} 
 
sub who_says_hello {  
    print(join(" ",caller), "\n"); 
    print "Hello, $_[0]\n"; 
} 
 
 
who_says_hello("World"); # <------ LINE 26 
 
print '-' x 20, "\n"; 
 
my $frame_wrapped_hello = trace_wrapper_frame(\&who_says_hello); 
$frame_wrapped_hello->("dolly"); 
 
print '-' x 20, "\n"; 
 
my $no_frame_wrapped_hello = trace_wrapper_no_frame(\&who_says_hello); 
$no_frame_wrapped_hello->("Fifty"); #<----- LINE 36