code: def test_vstack_2(a, b):
      ht = hl.utils.range_table(10)
  
      ht2 = ht.annotate(x=hl.nd.array(a), y=hl.nd.array(b))
      ht2 = ht2.annotate(stacked=hl.nd.vstack([ht2.x, ht2.y]))
      assert np.array_equal(ht2.collect()[0].stacked, np.vstack([a, b]))
  
imports: import math
  import numpy
  import re
  from ..helpers import *
  import pytest
  from hail.utils.java import FatalError, HailUserError
label_desc: Use image node_id 39 for calling a global function with example usage: test_vstack_2(a, b) without return types