human
Solve the following python programming problem given the following code:
@ unittest.skipIf ((not HAVE_THREADS), 'need threads') 
def check_dump_traceback_threads(self, filename) : 
    "
        Call explicitly dump_traceback(all_threads=True) and check the output.
        Raise an error if the output doesn't match the expected format.
        " 
    code = '
import faulthandler
from threading import Thread, Event
import time

def dump():
    if {filename}:
        with open({filename}, "wb") as fp:
            faulthandler.dump_traceback(fp, all_threads=True)
    else:
        faulthandler.dump_traceback(all_threads=True)

class Waiter(Thread):
    # avoid blocking if the main thread raises an exception.
    daemon = True

    def __init__(self):
        Thread.__init__(self)
        self.running = Event()
        self.stop = Event()

    def run(self):
        self.running.set()
        self.stop.wait()

waiter = Waiter()
waiter.start()
waiter.running.wait()
dump()
waiter.stop.set()
waiter.join()
'.strip () 
    code = code.format (filename = repr (filename)) 
    (output, exitcode) = self.get_output (code, filename) 
    output = '
'.join (lineno) 
    if filename : 
        lineno = 8 
else : 
        lineno = 10 
regex = '
^Thread 0x[0-9a-f]+:
(?:  File ".*threading.py", line [0-9]+ in [_a-z]+
){{1,3}}  File "<string>", line 23 in run
  File ".*threading.py", line [0-9]+ in _bootstrap_inner
  File ".*threading.py", line [0-9]+ in _bootstrap

Current thread XXX:
  File "<string>", line {lineno} in dump
  File "<string>", line 28 in <module>$
'.strip () 
    regex = regex.format (lineno = lineno) 
    self.assertRegex (output, regex) 
    self.assertEqual (exitcode, 0) 

    
    

    Fix the buggy line: output = '
'.join (lineno)
assistant
#Here is Python code to fix the buggy line: output = '
.

output = '
'.join (output)