Get the number of bytes received from the network for the response headers.
This value is available right before signalMessage::got-headers signal
is emitted, but you might get an intermediate value if called before.
For resources loaded from the disk cache this value is always 0.
Get the number of bytes received from the network for the response headers.
This value is available right before signalMessage::got-headers signal is emitted, but you might get an intermediate value if called before. For resources loaded from the disk cache this value is always 0.