keep_alive/4

Availability::- use_module(library(http/http_open)).

[det]keep_alive(+StreamPair, +Host, +In, -Left)

Callback when closing the range stream used to process the content of the reply. This callback makes the stream available for future keep-alive connections or closes the stream. The stream is closed if

There are too many bytes left unprocessed in the range stream.
There are too many pooled connections.