This actor delays its inputs by a variable delay.
It works in a similar way as the TimedDelay actor except that the
amount of time delayed is specified by an incoming token through
the delay port (a parameter port). If the delay is zero, then this
actor only increments the microstep, not the model time.
If a negative delay is specified, then an exception is thrown.
Jie Liu, Haiyang Zheng
$Id: VariableDelay.java 70398 2014-10-22 23:44:32Z cxh $
Ptolemy II 1.0
Green (hyzheng)
Yellow (hyzheng)
The amount specifying delay. Its default value is 1.0.