code: def simulationstep(timestep):
      
      if hydpy.pub.options.warnsimulationstep:
          warnings.warn(
              'Note that the applied function `simulationstep` is intended for '
              'testing purposes only.  When doing a HydPy simulation, parameter '
              'values are initialised based on the actual simulation time step '
              'as defined under `pub.timegrids.stepsize` and the value given '
              'to `simulationstep` is ignored.')
      parametertools.Parameter.simulationstep(timestep)
docs: Define a simulation time step size for testing purposes within a
      parameter control file.
  
      Using |simulationstep| only affects the values of time dependent
      parameters, when `pub.timegrids.stepsize` is not defined.  It thus has
      no influence on usual hydpy simulations at all.  Use it just to check
      your parameter control files.  Write it in a line immediately behind
      the one calling |parameterstep|.
  
      To clarify its purpose, executing raises a warning, when executing
      it from within a control file:
  
      >>> from hydpy import pub
      >>> with pub.options.warnsimulationstep(True):
      ...     from hydpy.models.hland_v1 import *
      ...     parameterstep('1d')
      ...     simulationstep('1h')
      Traceback (most recent call last):
      ...
      UserWarning: Note that the applied function `simulationstep` is intended \
  for testing purposes only.  When doing a HydPy simulation, parameter values \
  are initialised based on the actual simulation time step as defined under \
  `pub.timegrids.stepsize` and the value given to `simulationstep` is ignored.
      >>> k4.simulationstep
      Period('1h')