code: def test_static_vector_index(self):
      positive_axis = ps.non_negative_axis(axis=[0, -2], rank=4)
      self.assertAllEqual([0, 2], positive_axis)
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import dtype_util
  from tensorflow_probability.python.internal import prefer_static
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 3 for calling the NonNegativeAxisTest obj's underlying member method code with example usage: obj.test_static_vector_index() without return types