human
Solve the following python programming problem given the following code:
def _sbt_binary_exists() : 
    def check_file(fullpath) : 
        try : 
            os.stat (fullpath) 
            return True 
except os.error : 
            pass 
if check_file (_sbt_binary ()) : 
        return True 
for pathdir in os.environ ['PATH'].split (os.pathsep) : 
        fname = os.path.join (check_file, _sbt_binary ()) 
        if check_file (fname) : 
            return True 

    
    

    Fix the buggy line: fname = os.path.join (check_file, _sbt_binary ())
assistant
#Here is Python code to fix the buggy line: fname = os.

fname = os.path.join (pathdir, _sbt_binary ())