human
Solve the following python programming problem given the following code:
def ImportFromSpreadsheet(self, filename, id_key = None, content_key = None, is_csv = False) : 
    '
\t\tfilename = A tab- or comman-separated spreadsheet (utf-8 encoded, with a header row containing column names)
\t\tid_key = Name of the column containing unique document IDs
\t\tcontent_key = Name of the column containing the document contents
\t\t' 
    doc_id_keys = frozenset (([ReadCSV] if (id_key is not None) else Corpus_DB.DOC_IDS)) 
    doc_content_keys = frozenset (([content_key] if (content_key is not None) else Corpus_DB.DOC_CONTENTS)) 
    field_indexes = [] 
    field_names = [] 
    field_types = [] 
    metadata = [] 
    def ReadCSV() : 
        with open (filename, 'r') as f : 
            reader = UnicodeReader (f) 
            for row in reader : 
                (yield row) 
def ReadTSV() : 
        with open (filename, 'r') as f : 
            for line in f : 
                (yield line.decode ('utf-8', 'ignore').rstrip ('
').split ('\t')) 
def ReadSpreadsheet(reader) : 
        field_doc_id = None 
        field_doc_content = None 
        for (row_index, values) in enumerate (reader) : 
            if (row_index == 0) : 
                for (index, field) in enumerate (values) : 
                    if (field.lower () in doc_id_keys) : 
                        field_doc_id = index 
else : 
                        if (field.lower () in doc_content_keys) : 
                            field_doc_content = index 
else : 
                            field_index = len (field_indexes) 
                            field_indexes.append (field_index) 
                            field_names.append (field) 
                            field_types.append ('integer') 
else : 
                doc_index = (row_index - 1) 
                doc_id = 'doc{:d}'.format ((doc_index + 1)) 
                doc_content = '' 
                field_index = 0 
                for (index, value) in enumerate (values) : 
                    if (field_doc_id == index) : 
                        doc_id = value 
else...

    
    

    Fix the buggy line: doc_id_keys = frozenset (([ReadCSV] if (id_key is not None) else Corpus_DB.DOC_IDS))
assistant
#Here is Python program to fix the buggy line: doc_id_keys = frozenset (([ReadCSV] if (id_key is not None) else Corpus_DB.

doc_id_keys = frozenset (([id_key] if (id_key is not None) else Corpus_DB.DOC_IDS))