GROUP1 contains GROUP2, DEVICE1, DEVICE2, DEVICE3

GROUP2 contains GROUP3, GROUP4, DEVICE4, DEVICE5, USER1

GROUP3 contains GROUP5, USER2, DEVICE6, DEVICE7

GROUP4 contains DEVICE8, DEVICE9, USER2

USER1 contains DEVICE10, DEVICE11, DEVICE12

GROUP5 contains DEVICE13, DEVICE14

USER2 conatins DEVICE15, DEVICE16, DEVICE17