code: def test_minimum_eigen_vector(self):
      matrix = np.array([[1.0, 2.0], [2.0, 5.0]], dtype=np.float32)
      initial_vec = np.array([[1.0], [-1.0]], dtype=np.float32)
  
      def _vector_prod_fn(x):
          return tf.matmul(matrix, x)
  
      min_eigen_fn = autograph.to_graph(utils.minimum_eigen_vector)
      x = tf.placeholder(tf.float32, shape=(2, 1))
      min_eig_vec = min_eigen_fn(x, 10, 0.1, _vector_prod_fn)
      with self.test_session() as sess:
          v = sess.run(min_eig_vec, feed_dict={x: initial_vec})
          if v.flatten()[0] < 0:
              v = -v
      np.testing.assert_almost_equal(
          v, [[0.9239], [-0.3827]], decimal=4
      )
  
file_path: cleverhans/cleverhans_v3.1.0/cleverhans/experimental/certification/tests/utils_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  from scipy.sparse.linalg import eigs
  import tensorflow
  from tensorflow.contrib import autograph
  from cleverhans.experimental.certification import utils
label_desc: Use image node_id 1 for calling the UtilsTest obj's underlying member method code with example usage: obj.test_minimum_eigen_vector() and returns: tf