test
node1
GO:0018933
nicotine metabolic
process
node2
GO:0042179
nicotine biosynthetic
process
node1->node2
node3
GO:0008152
metabolic process
node4
GO:0009058
biosynthetic process
node3->node4
node3->node1
node4->node2
node5
BFO:0000003
occurrent
node5->node5
node6
BFO:0000015
process
node5->node6
node7
GO:0008150
biological_process
node6->node7
node7->node3
node8
BFO:0000001
entity
node8->node5