code: def update(self):
          
          con = self.subpars.pars.control
          self(con.eqi2*con.tind)
docs: Update |KI2| based on |EQI2| and |TInd|.
  
          >>> from hydpy.models.lland import *
          >>> parameterstep('1d')
          >>> eqi2(1.0)
          >>> tind.value = 10.0
          >>> derived.ki2.update()
          >>> derived.ki2
          ki2(10.0)