test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node3
GO:0008150
biological_process
node2->node3
node4
GO:0032501
multicellular
organismal process
node3->node4
node6
GO:0003008
system process
node4->node6
node5
BFO:0000001
entity
node5->node1
node7
GO:0003012
muscle system process
node6->node7
node8
GO:0006936
muscle contraction
node7->node8