code: def get_installed_power(self):
          r
          for wind_farm in self.wind_farms:
              wind_farm.installed_power = wind_farm.get_installed_power()
          return sum(wind_farm.installed_power for wind_farm in self.wind_farms)
docs: r"""
          Calculates the installed power of a wind turbine cluster.
  
          Returns
          -------
          float
              Installed power of the wind turbine cluster.