code: def calc_qt_v1(self):
      
      con = self.parameters.control.fastaccess
      flu = self.sequences.fluxes.fastaccess
      flu.qt = max(flu.outuh-con.abstr, 0.)
docs: Calculate the total discharge after possible abstractions.
  
      Required control parameter:
        |Abstr|
  
      Required flux sequence:
        |OutUH|
  
      Calculated flux sequence:
        |QT|
  
      Basic equation:
          :math:`QT = max(OutUH - Abstr, 0)`
  
      Examples:
  
          Trying to abstract less then available, as much as available and
          less then available results in:
  
          >>> from hydpy.models.hland import *
          >>> parameterstep('1d')
          >>> simulationstep('12h')
          >>> abstr(2.0)
          >>> fluxes.outuh = 2.0
          >>> model.calc_qt_v1()
          >>> fluxes.qt
          qt(1.0)
          >>> fluxes.outuh = 1.0
          >>> model.calc_qt_v1()
          >>> fluxes.qt
          qt(0.0)
          >>> fluxes.outuh = 0.5
          >>> model.calc_qt_v1()
          >>> fluxes.qt
          qt(0.0)
  
          Note that "negative abstractions" are allowed:
  
          >>> abstr(-2.0)
          >>> fluxes.outuh = 1.0
          >>> model.calc_qt_v1()
          >>> fluxes.qt
          qt(2.0)