def __init__(self, _factory=message.Message):
        self._factory = _factory
        self._input = BufferedSubFile()
        self._msgstack = []
        self._parse = self._parsegen().next
        self._cur = None
        self._last = None
        self._headersonly = False

    # Non-public interface for supporting Parser's headersonly flag
_factory is called with no arguments to create a new message obj
dataset/ETHPy150Open babble/babble/include/jython/Lib/email/feedparser.py/FeedParser.__init__