<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
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<USER_TASK:>
Description:
 def create_password_reset(cls, email, valid_for=3600) -> str:
 """
 Create a password reset request in the user_password_resets
 database table. Hashed code gets stored in the database.
 Returns unhashed reset code
 """

        user = cls.where_email(email)
        if user is None:
            return None
        PasswordResetModel.delete_where_user_id(user.id)
        token = JWT().create_token({
            'code': Security.random_string(5),  # make unique
            'user_id': user.id},
            token_valid_for=valid_for)
        code = Security.generate_uuid(1) + "-" + Security.random_string(5)
        password_reset_model = PasswordResetModel()
        password_reset_model.token = token
        password_reset_model.code = code
        password_reset_model.user_id = user.id
        password_reset_model.save()
        return code