Performs an action when method {@link #tryComplete} is invoked
and the pending count is zero, or when the unconditional
method {@link #complete} is invoked. By default, this method
does nothing. You can distinguish cases by checking the
identity of the given caller argument. If not equal to {@code
this}, then it is typically a subtask that may contain results
(and/or links to other results) to combine.
@param caller the task invoking this method (which may
be this task itself)
Performs an action when method {@link #tryComplete} is invoked and the pending count is zero, or when the unconditional method {@link #complete} is invoked. By default, this method does nothing. You can distinguish cases by checking the identity of the given caller argument. If not equal to {@code this}, then it is typically a subtask that may contain results (and/or links to other results) to combine.
@param caller the task invoking this method (which may be this task itself)