test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node8
GO:0008150
biological_process
node2->node8
node3
GO:0048878
chemical homeostasis
node4
GO:0050801
monoatomic ion
homeostasis
node3->node4
node6
GO:0055080
monoatomic cation
homeostasis
node4->node6
node5
GO:0042592
homeostatic process
node5->node3
node7
BFO:0000001
entity
node7->node1
node8->node5