Returns and sends a copy of the message with the specified
arguments
to start processing, while the sender also continues processing.
As this method, other than the similar method
startWith
,
starts a copy of the message, it can be called multiple times with the
same receiving message.
If
target is specified,
the message is sent to
target
and both the receiving message and the message copy are changed to use
the new
target.
Otherwise the message is sent to the target the message object provides.
The
arguments array items are used as
message arguments and both the receiving message and the message copy
are changed to use these new
arguments.
This method returns as soon as possible and does not wait until
message processing is complete.
The
notify
method can be used to request notification that message processing is complete.
When message processing is complete, the message object retains any
result and holds it until requested via the
result method.
