code: def test_bh_update_position():
      def square(x):
          return np.sum(x**2)
  
      new_function = function.Function(pointer=square)
  
      new_bh = bh.BH()
  
      search_space = search.SearchSpace(
          n_agents=20,
          n_variables=2,
          lower_bound=[0, 0],
          upper_bound=[10, 10],
      )
  
      cost = new_bh._update_position(
          search_space.agents, search_space.best_agent, new_function
      )
  
      assert cost != 0
  
imports: import numpy
  from opytimizer.core import function
  from opytimizer.optimizers.science import bh
  from opytimizer.spaces import search
label_desc: Use image node_id 1 for calling a global function with example usage: test_bh_update_position() and returns: np