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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 ensure_connection(self, errback=None, max_retries=None, interval_start=2, interval_step=2, interval_max=30):
 """Ensure we have a connection to the server. If not retry establishing the connection with the settings specified. :keyword errback: Optional callback called each time the connection can't be established. Arguments provided are the exception raised and the interval that will be slept ``(exc, interval)``. :keyword max_retries: Maximum number of times to retry. If this limit is exceeded the connection error will be re-raised. :keyword interval_start: The number of seconds we start sleeping for. :keyword interval_step: How many seconds added to the interval for each retry. :keyword interval_max: Maximum number of seconds to sleep between each retry. """

        retry_over_time(self.connect, self.connection_errors, (), {},
                        errback, max_retries,
                        interval_start, interval_step, interval_max)
        return self