test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node3
GO:0008150
biological_process
node2->node3
node4
GO:0008152
metabolic process
node3->node4
node5
GO:0044281
small molecule
metabolic process
node4->node5
node6
GO:0006766
vitamin metabolic
process
node5->node6
node8
GO:0006767
water-soluble vitamin
metabolic process
node6->node8
node7
BFO:0000001
entity
node7->node1