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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 create(self, key, value):
 """ Create a new VariableInstance :param unicode key: The key :param unicode value: The value :returns: Newly created VariableInstance :rtype: twilio.rest.serverless.v1.service.environment.variable.VariableInstance """

        data = values.of({'Key': key, 'Value': value, })

        payload = self._version.create(
            'POST',
            self._uri,
            data=data,
        )

        return VariableInstance(
            self._version,
            payload,
            service_sid=self._solution['service_sid'],
            environment_sid=self._solution['environment_sid'],
        )