code: def test_weo_evaporation_flux():
      new_weo = weo.WEO()
  
      theta = np.pi
  
      J = new_weo._evaporation_flux(theta)
  
      assert J == 0.6349860094028128
  
imports: import numpy
  from opytimizer.optimizers.science import weo
  from opytimizer.spaces import search
label_desc: Use image node_id 3 for calling a global function with example usage: test_weo_evaporation_flux() without return types