How to use the tinytag.tinytag.ID3.ID3V1_GENRES function in tinytag

def _set_field(self, fieldname, bytestring, transfunc=None):
        """convienience function to set fields of the tinytag by name.
        the payload (bytestring) can be changed using the transfunc"""
        if getattr(self, fieldname):  # do not overwrite existing data
            return
        value = bytestring if transfunc is None else transfunc(bytestring)
        if DEBUG:
            stderr('Setting field "%s" to "%s"' % (fieldname, value))
        if fieldname == 'genre' and value.isdigit() and int(value) < len(ID3.ID3V1_GENRES):
            # funky: id3v1 genre hidden in a id3v2 field
            value = ID3.ID3V1_GENRES[int(value)]
        if fieldname in ("track", "disc"):
            if type(value).__name__ in ('str', 'unicode') and '/' in value:
                current, total = value.split('/')[:2]
                setattr(self, "%s_total" % fieldname, total)
            else:
                current = value
            setattr(self, fieldname, current)
        else:
            setattr(self, fieldname, value)

def _set_field(self, fieldname, bytestring, transfunc=None):
        """convienience function to set fields of the tinytag by name.
        the payload (bytestring) can be changed using the transfunc"""
        if getattr(self, fieldname):  # do not overwrite existing data
            return
        value = bytestring if transfunc is None else transfunc(bytestring)
        if DEBUG:
            stderr('Setting field "%s" to "%s"' % (fieldname, value))
        if fieldname == 'genre' and value.isdigit() and int(value) < len(ID3.ID3V1_GENRES):
            # funky: id3v1 genre hidden in a id3v2 field
            value = ID3.ID3V1_GENRES[int(value)]
        if fieldname in ("track", "disc"):
            if type(value).__name__ in ('str', 'unicode') and '/' in value:
                current, total = value.split('/')[:2]
                setattr(self, "%s_total" % fieldname, total)
            else:
                current = value
            setattr(self, fieldname, current)
        else:
            setattr(self, fieldname, value)