code: def test_get_n_trees():
      i = AnnoyIndex(10, "angular")
      i.load("test/test.tree")
      assert i.get_n_trees() == 10
  
imports: import os
  import random
  import pytest
  from annoy import AnnoyIndex
label_desc: Use image node_id 18 for calling a global function with example usage: test_get_n_trees() without return types