test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node3
GO:0008150
biological_process
node2->node3
node4
GO:0009987
cellular process
node3->node4
node6
GO:0043335
protein unfolding
node4->node6
node5
BFO:0000001
entity
node5->node1