code: def test_pushes_and_pops(self):
      stack = Stack.create(7, jnp.zeros((), jnp.int32))
      stack = stack.push(jnp.int32(7))
      self.assertFalse(stack.empty())
      stack = stack.push(jnp.int32(8))
      self.assertFalse(stack.empty())
      x, stack = stack.pop()
      self.assertFalse(stack.empty())
      self.assertEqual(8, x)
      stack = stack.push(jnp.int32(9))
      x, stack = stack.pop()
      self.assertFalse(stack.empty())
      self.assertEqual(9, x)
      x, stack = stack.pop()
      self.assertTrue(stack.empty())
      self.assertEqual(7, x)
  
file_path: jax/tests/stack_test.py
imports: from absl.testing import absltest
  import jax.numpy
  from jax._src.lax.stack import Stack
  from jax._src import test_util
  from jax import config
label_desc: Use image node_id 2 for calling the StackTest obj's underlying member method code with example usage: obj.test_pushes_and_pops() without return types