code: def _packetlist_timeskew_graph(self, ip, **kargs):
      
      res = map(lambda x: self._elt2pkt(x), self.res)
      b = filter(lambda x: x.haslayer(IP) and x.getlayer(IP).src == ip and x.haslayer(TCP), res)
      c = []
      for p in b:
          opts = p.getlayer(TCP).options
          for o in opts:
              if o[0] == "Timestamp":
                  c.append((p.time, o[1][0]))
      if not c:
          warning("No timestamps found in packet list")
          return
      # d = map(lambda (x,y): (x%2000,((x-c[0][0])-((y-c[0][1])/1000.0))),c)
      d = map(lambda a: (a[0] % 2000, ((a[0] - c[0][0]) - ((a[1] - c[0][1]) / 1000.0))), c)
      return plt.plot(d, **kargs)
docs: Tries to graph the timeskew between the timestamps and real time for a given ip