Returns the result (if any) of sending the message with the specified
arguments.
If
target is specified,
the message is sent to
target
and the receiving message object is 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 the receiving message object is changed to use these
new
arguments.
This method does not return 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.
