An event indicating that the amount of bytes has been sent over the network, such as when sending
request headers or uploading request body bytes. This includes localhost requests. Currently,
this is only implemented for HTTP transactions, and the amount of bytes does not include TLS
overhead or TCP retransmits.
Returns the URL request associated with the response.
default int count()
Returns the number of bytes measured at the application layer that have been sent over the
network for this request since the last time this event was called. It will always be greater
than 0 and will not include TLS overhead or TCP retransmits.