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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 decrypt(self, value):
 """Decrypt session data."""

        try:
            value, timestamp, signature = value.split("|")
        except ValueError:
            return None
        if check_signature(signature, self.secret, value + timestamp, encoding=self.encoding):
            return base64.b64decode(value).decode(self.encoding)