human
Solve the following python programming problem given the following code:
def _format_node(self, op) : 
    formatted_args = [] 
    def visit(what, extra_indents = 0) : 
        if isinstance (what, ir.Expr) : 
            result = self._format_subexpr (what) 
else : 
            result = self._indent (str (what)) 
if (extra_indents > 0) : 
            result = util.indent (result, self.indent_size) 
formatted_args.append (result) 
arg_names = getattr (op, '_arg_names', None) 
    if (arg_names is None) : 
        for arg in op.args : 
            if isinstance (arg, list) : 
                for x in arg : 
                    visit (x) 
else : 
                visit (arg) 
else : 
        for (arg, name) in zip (op.args, arg_names) : 
            if (name is not None) : 
                name = self._indent ('{0}:'.format (name)) 
if isinstance (arg, list) : 
                if ((name is not None) and (len (arg) > 0)) : 
                    formatted_args.append (name) 
                    indents = 1 
else : 
                    indents = 0 
for x in arg : 
                    visit (arg_names, extra_indents = indents) 
else : 
                if (name is not None) : 
                    formatted_args.append (name) 
                    indents = 1 
else : 
                    indents = 0 
visit (arg, extra_indents = indents) 
opname = type (op).__name__ 
    type_display = self._get_type_display (op) 
    opline = ('%s[%s]' % (opname, type_display)) 
    return '
'.join (([opline] + formatted_args)) 

    
    

    Fix the buggy line: visit (arg_names, extra_indents = indents)
assistant
#Here is Python code to fix the buggy line: visit (arg_names, extra_indents = indents)
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visit (x, extra_indents = indents)