code: def test_stacking(self):
      self.assertEqual(tf.Variable(0, name="x").name, "x:0")
      with name_scope("outer") as outer:
          self.assertEqual(outer.name, "outer")
          self.assertEqual(tf.Variable(0, name="x").name, "outer/x:0")
          with name_scope("middle") as middle:
              self.assertEqual(middle.name, "middle")
              self.assertEqual(
                  tf.Variable(0, name="x").name, "outer/middle/x:0"
              )
              with name_scope("inner") as inner:
                  self.assertEqual(inner.name, "inner")
                  self.assertEqual(
                      tf.Variable(0, name="x").name,
                      "outer/middle/inner/x:0",
                  )
              self.assertEqual(
                  tf.Variable(0, name="x").name, "outer/middle/x:0"
              )
          self.assertEqual(tf.Variable(0, name="x").name, "outer/x:0")
      self.assertEqual(tf.Variable(0, name="x").name, "x:0")
  
imports: import tensorflow
  from keras.backend.tensorflow.core import name_scope
  from keras.testing import TestCase
label_desc: Use image node_id 1 for calling the TFNameScopeTest obj's underlying member method code with example usage: obj.test_stacking() without return types