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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def calc_evpo_v1(self):
 """Calculate land use and month specific values of potential evapotranspiration. Required control parameters: |NHRU| |Lnk| |FLn| Required derived parameter: |MOY| Required flux sequence: |ET0| Calculated flux sequence: |EvPo| Additional requirements: |Model.idx_sim| Basic equation: :math:`EvPo = FLn \\cdot ET0` Example: For clarity, this is more of a kind of an integration example. Parameter |FLn| both depends on time (the actual month) and space (the actual land use). Firstly, let us define a initialization time period spanning the transition from June to July: Secondly, assume that the considered subbasin is differenciated in two HRUs, one of primarily consisting of arable land and the other one of deciduous forests: Thirdly, set the |FLn| values, one for the relevant months and land use classes: Fourthly, the index array connecting the simulation time steps from the |pub| module. This can be done manually more conveniently via its update method: moy(5, 6) Finally, the actual method (with its simple equation) is applied as usual: evpo(2.598, 2.7) evpo(2.608, 2.73) Reset module |pub| to not interfere the following examples: """

    con = self.parameters.control.fastaccess
    der = self.parameters.derived.fastaccess
    flu = self.sequences.fluxes.fastaccess
    for k in range(con.nhru):
        flu.evpo[k] = con.fln[con.lnk[k]-1, der.moy[self.idx_sim]] * flu.et0[k]