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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 validate_password(self, password):
 """ Check the password against existing credentials. :param password: the password that was provided by the user to try and authenticate. This is the clear text version that we will need to match against the hashed one in the database. :type password: unicode object. :return: Whether the password is valid. :rtype: bool """

        hash = sha256()
        hash.update((password + self.password[:64]).encode('utf-8'))
        return self.password[64:] == hash.hexdigest()