def METHOD_NAME(self, stream_name: str, record: Mapping):
    """
    Populates input records to `records_buffer`.
    1) normalizes input record
    2) coerces normalized record to str
    3) gets values as list of record values from record mapping.
    """
    norm_record = self._normalize_record(stream_name, record)
    norm_values = list(map(str, norm_record.values()))
    self.records_buffer[stream_name].append(norm_values)