code: def prepare_io_example_1() -> Tuple[devicetools.Nodes, devicetools.Elements]:
      from hydpy import TestIO
      TestIO.clear()
      from hydpy.core.filetools import SequenceManager
      hydpy.pub.sequencemanager = SequenceManager()
      with TestIO():
          hydpy.pub.sequencemanager.inputdirpath = 'inputpath'
          hydpy.pub.sequencemanager.fluxdirpath = 'outputpath'
          hydpy.pub.sequencemanager.statedirpath = 'outputpath'
          hydpy.pub.sequencemanager.nodedirpath = 'nodepath'
      hydpy.pub.timegrids = '2000-01-01', '2000-01-05', '1d'
      from hydpy import Node, Nodes, Element, Elements, prepare_model
      node1 = Node('node1')
      node2 = Node('node2', variable='T')
      nodes = Nodes(node1, node2)
      element1 = Element('element1', outlets=node1)
      element2 = Element('element2', outlets=node1)
      element3 = Element('element3', outlets=node1)
      elements = Elements(element1, element2, element3)
      from hydpy.models import lland_v1, lland_v2
      element1.model = prepare_model(lland_v1)
      element2.model = prepare_model(lland_v1)
      element3.model = prepare_model(lland_v2)
      from hydpy.models.lland import ACKER
      for idx, element in enumerate(elements):
          parameters = element.model.parameters
          parameters.control.nhru(idx+1)
          parameters.control.lnk(ACKER)
          parameters.derived.absfhru(10.0)
      with hydpy.pub.options.printprogress(False):
          nodes.prepare_simseries()
          elements.prepare_inputseries()
          elements.prepare_fluxseries()
          elements.prepare_stateseries()
      def init_values(seq, value1_):
          value2_ = value1_ + len(seq.series.flatten())
          values_ = numpy.arange(value1_, value2_, dtype=float)
          seq.testarray = values_.reshape(seq.seriesshape)
          seq.series = seq.testarray.copy()
          return value2_
      import numpy
      value1 = 0
      for subname, seqname in zip(['inputs', 'fluxes', 'states'],
                                  ['nied', 'nkor', 'bowa']):
          for element in elements:
              subseqs = getattr(element.model.sequences, subname)
              value1 = init_values(getattr(subseqs, seqname), value1)
      for node in nodes:
          value1 = init_values(node.sequences.sim, value1)
      return nodes, elements