def DocumentStart(self, event, loader):
    assert self._stack == []
    self._Push(_TOKEN_DOCUMENT, self._builder.BuildDocument())
flag ::= "\Answered" / "\Flagged" / "\Deleted" /
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/yaml_builder.py/BuilderHandler.DocumentStart--crossover with--dataset/ETHPy150Open scanner/asimap/asimap/parse.py/IMAPClientCommand._p_flag