cceed if it is unable to
										be canceled. If the task is canceled, then its <a href="joinandreceiveindextask.html#run">run</a> function will reject
										the promise. If <a href="joinandreceiveindextask.html#cancel">cancel</a> is called before <a href="joinandreceiveindextask.html#run">run</a>, then <a href="joinandreceiveindextask.html#run">run</a>
										must immediately reject the returned promise. If <a href="joinandreceiveindextask.html#cancel">cancel</a> is called
									after <a href="