def __init__(self, postreader, excludes):
        
        self.postreader = postreader
        if hasattr(postreader, "format"):
            self.format = postreader.format
        
        self.excludes = excludes
        self._find_nonexcluded()
        self.value = postreader.value
:param postreader: the PostingReader object to read from.
dataset/ETHPy150Open dokipen/whoosh/src/whoosh/postings.py/Exclude.__init__