code: def test_abs(self):
      with self.test_session() as sess:
          x = Normal(0.0, 1.0)
          z = abs(x)
          z_value = abs(x.value())
          z_eval, z_value_eval = sess.run([z, z_value])
          self.assertAllEqual(z_eval, z_value_eval)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import edward
  import tensorflow
  from edward.models import Normal
label_desc: Use image node_id 21 for calling the test_random_variable_operators_class obj's underlying member method code with example usage: obj.test_abs() without return types