• '_prologue_' is an imaginary function that initialize argc, argv
  
• Solid arrow means call edge
  
• Dotted arrow means return edge
  
• Green arrow means branch (pair of call & return)
  
For details, see II-A.'Backbone-Branch Decomposition' section of our paper

Path should NOT have an incoming edge to 'print_random', because tainted data cannot flow through the node