code: def test_quadratics(self):
      def test_random_quadratic(dim, seed):
          """Generates random test case for function x^T A x + b x."""
          np.random.seed(seed)
          a = np.random.uniform(size=(dim, dim))
          a = np.array(
              np.dot(a, a.T), dtype=np.float64
          )  # Must be positive semidefinite.
          b = np.array(np.random.uniform(size=(dim,)), dtype=np.float64)
          argmin = -np.dot(np.linalg.inv(a), b)
          a = tf.constant(a)
          b = tf.constant(b)
  
          def paraboloid(x):
              return 0.5 * tf.einsum("i,ij,j->", x, a, x) + tf.einsum(
                  "i,i->", b, x
              )
  
          self._check_algorithm(
              start_point=np.random.uniform(size=(dim,)),
              func=paraboloid,
              expected_argmin=argmin,
          )
  
      test_random_quadratic(2, 43)
      test_random_quadratic(3, 43)
      test_random_quadratic(4, 43)
      test_random_quadratic(5, 43)
      test_random_quadratic(10, 43)
      test_random_quadratic(15, 43)
  
imports: import numpy
  import tensorflow.compat.v2
  import tf_quant_finance
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 3 for calling the ConjugateGradientTest obj's underlying member method code with example usage: obj.test_quadratics() and returns: unknown