human
Solve the following python programming problem given the following code:
@ classmethod 
def make_unique(cls, filename, force = True) : 
    'Generates a unique filename if the file already exists

        :param filename:
        :return:
        ' 
    import uuid 
    def generate_filename() : 
        random_part = uuid.uuid4 ().hex [(- 4) :] 
        data = os.path.splitext (filename) 
        return ('%s_%s%s' % (data [0], random_part, data [1])) 
if (not force) : 
        if os.path.exists (filename) : 
            new_filename = generate_filename () 
            while os.path.exists (filename) : 
                new_filename = generate_filename () 
return new_filename 
else : 
            return filename 
else : 
        return generate_filename () 

    
    

    Fix the buggy line: while os.path.exists (filename) :
assistant
#Here is Python program to fix the buggy line: while os.

while os.path.exists (new_filename) :