Manages persistent connections using Net::HTTP including a thread pool for
connecting to multiple hosts.
Using persistent HTTP connections can dramatically increase the speed of HTTP.
Creating a new HTTP connection for every request involves an extra TCP
round-trip and causes TCP congestion avoidance negotiation to start over.
Net::HTTP supports persistent connections with some API methods but does not
make setting up a single persistent connection or managing multiple
connections easy. Net::HTTP::Persistent wraps Net::HTTP and allows you to
focus on how to make HTTP requests.