test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node3
GO:0008150
biological_process
node2->node3
node7
GO:0008152
metabolic process
node3->node7
node4
BFO:0000001
entity
node4->node1
node5
GO:0071704
organic substance
metabolic process
node6
GO:0015977
carbon fixation
node5->node6
node7->node5