code: def trim(self, lower=None, upper=None):
          
          pwmax = self.subseqs.seqs.model.parameters.control.pwmax
          waes = self.subseqs.waes
          if lower is None:
              lower = numpy.clip(waes/pwmax, 0., numpy.inf)
              lower[numpy.isnan(lower)] = 0.0
          lland_sequences.State1DSequence.trim(self, lower, upper)
docs: Trim values in accordance with :math:`WAeS \\leq PWMax \\cdot WATS`,
          or at least in accordance with if :math:`WATS \\geq 0`.
  
          >>> from hydpy.models.lland import *
          >>> parameterstep('1d')
          >>> nhru(7)
          >>> pwmax(2.0)
          >>> states.waes = -1., 0., 1., -1., 5., 10., 20.
          >>> states.wats(-1., 0., 0., 5., 5., 5., 5.)
          >>> states.wats
          wats(0.0, 0.0, 0.5, 5.0, 5.0, 5.0, 10.0)