If true the event source supports setting HTTP headers.
If true the event source supports read timeouts. A read timeout for an event source represents the maximum time between receiving any data. If you receive 1 byte, and then a period of time greater than the read time out elapses, and you do not receive a second byte, then that would cause the event source to timeout.
It is not a timeout for the read of the entire body, which should be indefinite.
If true the event source supports customized verbs POST/REPORT instead of only the default GET.