The present invention provides a method and system for user-localizable hierarchical lists. A diameter-reduced water passage 19 of a flow control member 20 disposed in a head portion 22 of a shower head body 12 has a first and a second water passage portions 40 and 41 provided on an entry side and an exit side thereof, respectively. Some sequences of operations in the process are unfeasible. One or more other nodes associated with a service with which the OAM address is associated may be notified that the OAM address is associated with the provider network node that owns the OAM address. When the problem is reproduced, these data are used to simulate the situation at the time of problem occurrence by using simulation unit. A cross-over member is located on the other side of the planar central portion and include flow passage that communicate with inlet and outlet manifolds formed in the base member.