code: def commonpath(l1, l2, common=[]):
      if len(l1) < 1:
          return (common, l1, l2)
      if len(l2) < 1:
          return (common, l1, l2)
      if l1[0] != l2[0]:
          return (common, l1, l2)
      return commonpath(l1[1:], l2[1:], common + [l1[0]])
  
imports: import os.path
  from utility import to_seq
  from glob import glob
  from b2.util import bjam_signature
label_desc: Use image node_id 17 for calling a global function with example usage: commonpath(l1, l2, common) and returns: commonpath, common,  l1,  l2, common,  l1,  l2, common,  l1,  l2