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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _safe_readinto(self, b):
 """Same as _safe_read, but for reading into a buffer."""

        total_bytes = 0
        mvb = memoryview(b)
        while total_bytes < len(b):
            if MAXAMOUNT < len(mvb):
                temp_mvb = mvb[0:MAXAMOUNT]
                n = self.fp.readinto(temp_mvb)
            else:
                n = self.fp.readinto(mvb)
            if not n:
                raise IncompleteRead(bytes(mvb[0:total_bytes]), len(b))
            mvb = mvb[n:]
            total_bytes += n
        return total_bytes