code: def get_arcs(analysis):
          
          if not analysis.has_arcs():
              return None
  
          branch_lines = analysis.branch_lines()
          branches = []
  
          for l1, l2 in analysis.arcs_executed():
              if l1 in branch_lines:
                  branches.extend((l1, 0, abs(l2), 1))
  
          for l1, l2 in analysis.arcs_missing():
              if l1 in branch_lines:
                  branches.extend((l1, 0, abs(l2), 0))
  
          return branches
docs: Hit stats for each branch.
  
          Returns a flat list where every four values represent a branch:
          1. line-number
          2. block-number (not used)
          3. branch-number
          4. hits (we only get 1/0 from coverage.py)