A frame, and optional callback, intended for the network layer.
<p>
Note: the frame can undergo many transformations in the various
layers and extensions present in the implementation.
<p>
If you are implementing a mutation, you are obliged to handle
the incoming WriteCallback appropriately.
@param frame the frame to eventually write to the network layer.
@param callback the callback to notify when the frame is written.
A frame, and optional callback, intended for the network layer. <p> Note: the frame can undergo many transformations in the various layers and extensions present in the implementation. <p> If you are implementing a mutation, you are obliged to handle the incoming WriteCallback appropriately.
@param frame the frame to eventually write to the network layer. @param callback the callback to notify when the frame is written.