test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node5
GO:0003674
molecular_function
node2->node5
node3
GO:0005488
binding
node4
GO:0042165
neurotransmitter
binding
node3->node4
node5->node3
node6
BFO:0000001
entity
node6->node1