code: def test_powersystem_small() -> None:
      np.random.seed(12)
      dams = 2
      func = core.PowerSystem(num_dams=dams, num_years=0.2)
      x = [np.random.rand(func.dimension // dams) for _ in range(dams)]
      value = func.function(*x)
      np.testing.assert_almost_equal(value, 4266.8177479)
  
imports: import typing
  from unittest.mock import patch
  import numpy
  from .None import core
label_desc: Use image node_id 1 for calling a global function with example usage: test_powersystem_small() without return types