def is_completed(self):
mask = Task.NOT_FINISHED_MASK<EOL>iter = Task.Iterator(self.task_tree, mask)<EOL>try:<EOL><INDENT>next(iter)<EOL><DEDENT>except StopIteration:<EOL><INDENT>return True<EOL><DEDENT>return False<EOL>
Returns True if the entire Workflow is completed, False otherwise.

:rtype: bool
:return: Whether the workflow is completed.