[ACCIDENT] ・aSender に OhPort 型変数が格納されていない場合。 [in] aSender - the sender casted to OhPort. Returns "true" if the setting was successfull. For the following cases, it returns "false".
aSender is null.
already the sender has been set.
the type of datapacks which "aSender" treats is different from that of datapacks which this ports treats.