anchor.diff:        instructions: []
         split_by_var: ''
   ----
  -<1> each stream point to the next stream
  -<2> last point to the first 
  -<3> the number of loop is given in `action_count: 1`
  -<4> self_start is disabled for all the streams except the first one
  -
  +<1> Each stream point to the next stream
  +<2> Last point to the first 
  +<3> The number of loop is given in `action_count: 1`
  +<4> Self_start is disabled for all the streams except the first one
   
   ==== Tutorial: Pcap file to many streams and Field Engine 
   
  
positive.code:                                            |   WORK (pause) -> PAUSE (resume )---
                                             |                                     | 
                                             |                                     |
                                          ------------------------------------                                    
  
  -----
  
  
negative.code: 
  ==== Tutorial: Mask instruction 
  
  The STLVmWrMaskFlowVar is a handy instruction. The pseudocode is as follows:
  
  .Pseudocode 
  [source,bash]
  