| 178 |  | ... | 
          
            | 179 |  | self.wdmLink(roadm2, roadm3, LINEOUT, LINEIN, spans=[22*km]) | 
          
            | 180 |  | self.wdmLink(roadm3, roadm2, LINEOUT, LINEIN, spans=[22*km]) | 
          
            |  | 178 | self.wdmLink(roadm4, roadm1, LINEOUT, LINEIN) | 
          
            |  | 179 | self.wdmLink(roadm1, roadm4, LINEOUT, LINEIN) | 
          
            |  | 180 | self.wdmLink(roadm1, roadm2, DROP+1, ADD+1)  # passthrough | 
          
            |  | 181 | self.wdmLink(roadm2, roadm1, DROP+1, ADD+1)  # passthrough | 
          
            |  | 182 | # Sub-millisecond delays won't be accurate (due to scheduler timing | 
          
            |  | 183 | # granularity and running in a VM) but this will add observable | 
          
            |  | 184 | # propagation delay for the longer links. | 
          
            |  | 185 | self.wdmLink(roadm2, roadm3, LINEOUT, LINEIN, spans=[22*km], delay='73us') | 
          
            |  | 186 | self.wdmLink(roadm3, roadm2, LINEOUT, LINEIN, spans=[22*km], delay='73us') |