A backoff manager implementation that uses an exponential backoff algorithm to adjust the maximum number of connections per HTTP route. The algorithm reduces the number of connections in response to adverse events, such as connection failures, and gradually increases the number of connections when the route is operating without issues.

This implementation is specifically designed for managing connections in an HTTP route context and provides methods for probing and backing off connections based on the performance of the route.

The exponential backoff algorithm is primarily implemented in the getBackedOffPoolSize method, which calculates the new connection pool size based on the current pool size, growth rate, and the number of time intervals.