test
node1
BFO:0000001
entity
node2
BFO:0000003
occurrent
node1->node2
node2->node2
node5
BFO:0000015
process
node2->node5
node3
GO:0032502
developmental process
node4
GO:0098727
maintenance of cell
number
node3->node4
node6
GO:0008150
biological_process
node5->node6
node6->node3