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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 read(self, size=-1):
 """Read up to size decrypted bytes"""

        self._check_not_closed()
        if self.state == "EOF" or size == 0:
            return b""
        elif size < 0:
            return self._read_all()
        else:
            return self._read_block(size)