func_code: def union(f1con, f2con):
      d1 = {}
      union = []
      i = 0
      while i != len(f1con):
          line = f1con[i]
          d1[line] = True
          i = i + 1
      i = 0
      while i != len(f2con):
          line = f2con[i]
          if line in list(d1.keys()):
              union.append(line)
          i = i + 1
      union = sorted(list(set(union)))
      return union