in amazon_transcribe/structures.py [0:0]
    def readinto(self, b, read1=False):
        if not isinstance(b, memoryview):
            b = memoryview(b)
            b = b.cast("B")
        if read1:
            data = self.read1(len(b))
        else:
            data = self.read(len(b))
        if data is None:
            raise BlockingIOError("readinto")
        n = len(data)
        b[:n] = data
        return n