human
Solve the following python programming problem given the following code:
def ErrorContextPrinter(header, empty, modifier = None, singleton = None) : 
    "Creates a function that prints extra error data.

  Args:
    header: What to print before the data.
    empty: What to print when there's no data.
    modifier: Optional, run on all the data before printing.
    singleton: Optional, what to print when there's only one datum.
  Returns:
    Function that takes (data, printer) and prints the data using the printer.
  " 
    def WriteExtraData(data, printer) : 
        data = list ((modifier (data) if modifier else data)) 
        if data : 
            if ((not singleton) or (len (data) > 1)) : 
                printer (header, end = ':
') 
                for datum in data : 
                    if (datum is None) : 
                        printer ('') 
else : 
                        printer (str (datum)) 
else : 
                printer ((singleton % data [0])) 
else : 
            printer (empty) 
return empty 

    
    

    Fix the buggy line: return empty
assistant
#Here is Python program to fix the buggy line: return empty
.

return def WriteExtraData(