code: def test_tree_space_create_trees():
      new_tree_space = tree.TreeSpace(2, 1, 0, 1)
  
      new_tree_space._create_trees()
  
      assert len(new_tree_space.trees) == 2
  
imports: from opytimizer.core import node
  from opytimizer.spaces import tree
label_desc: Use image node_id 16 for calling a global function with example usage: test_tree_space_create_trees() without return types