How to use the isbntools.dev._exceptions.RecordMappingError function in isbntools

def _mapper(isbn, records):
    """Mapp: canonical <- records."""
    # canonical: ISBN-13, Title, Authors, Publisher, Year, Language
    try:
        canonical = {}
        canonical['ISBN-13'] = u(isbn)
        canonical['Title'] = records.get('title', u('')).replace(' :', ':')
        buf = records.get('author', u(''))
        canonical['Authors'] = [x.strip('. ') for x in buf.split(';')]
        canonical['Publisher'] = records.get('publisher', u(''))
        canonical['Year'] = records.get('year', u(''))
        canonical['Language'] = records.get('lang', u(''))
    except:  # pragma: no cover
        raise RecordMappingError(isbn)
    # call stdmeta for extra cleanning and validation
    return stdmeta(canonical)

def _mapper(isbn, records):
    """Map canonical <- records."""
    # canonical:
    # -> ISBN-13, Title, Authors, Publisher, Year, Language
    try:
        # mapping: canonical <- records
        canonical = {}
        canonical['ISBN-13'] = u(isbn)
        canonical['Title'] = records.get('title', u('')).replace(' :', ':')
        canonical['Authors'] = [a['name'] for a in
                                records.get('authors', ({'name': u('')},))]
        canonical['Publisher'] = records.get('publishers',
                                             [{'name': u('')}, ])[0]['name']
        canonical['Year'] = records.get('publish_date', u(',')).split(',')[1]
    except:   # pragma: no cover
        raise RecordMappingError(isbn)
    # call stdmeta for extra cleanning and validation
    return stdmeta(canonical)

"""Mapp: canonical <- records."""
    # canonical: ISBN-13, Title, Authors, Publisher, Year, Language
    try:
        canonical = {}
        canonical['ISBN-13'] = u(isbn)
        canonical['Title'] = records.get('title', u('')).replace(' :', ':')
        canonical['Authors'] = records.get('authors', [u('')])
        canonical['Publisher'] = records.get('publisher', u(''))
        if 'publishedDate' in records \
           and len(records['publishedDate']) >= 4:
            canonical['Year'] = records['publishedDate'][0:4]
        else:         # pragma: no cover
            canonical['Year'] = u('')
        canonical['Language'] = records.get('language', u(''))
    except:           # pragma: no cover
        raise RecordMappingError(isbn)
    # call stdmeta for extra cleanning and validation
    return stdmeta(canonical)

isbn = ident['identifier']
                break
        if not isbn:  # pragma: no cover
            return
        canonical['ISBN-13'] = isbn
        canonical['Title'] = record.get('title', u('')).replace(' :', ':')
        canonical['Authors'] = record.get('authors', [])
        canonical['Publisher'] = record.get('publisher', u(''))
        if 'publishedDate' in record \
           and len(record['publishedDate']) >= 4:
            canonical['Year'] = record['publishedDate'][0:4]
        else:         # pragma: no cover
            canonical['Year'] = u('')
        canonical['Language'] = record.get('language', u(''))
    except:           # pragma: no cover
        raise RecordMappingError(isbn)
    # call stdmeta for extra cleanning and validation
    return stdmeta(canonical)

# mapping: canonical <- records
        canonical = {}
        canonical['ISBN-13'] = u(isbn)
        # assert isbn == records['isbn13'], "isbn was mungled!"
        canonical['Title'] = records.get('title', u(''))
        authors = [a['name'] for a in records['author_data']]
        canonical['Authors'] = authors
        canonical['Publisher'] = records.get('publisher_name', u(''))
        canonical['Year'] = u('')
        if 'edition_info' in records:
            match = re.search(PATT_YEAR, records['edition_info'])
            if match:
                canonical['Year'] = str(match.group(0))
        canonical['Language'] = records.get('language', u(''))
    except:
        raise RecordMappingError(isbn)
    # call stdmeta for extra cleanning and validation
    return stdmeta(canonical)