code: def test_multiple_functions(self):
      # Define 3 independednt quadratic functions, each with its own minimum.
      minima = np.array([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]])
      func = lambda x: tf.reduce_sum(tf.square(x - minima), axis=1)
      self._check_algorithm(
          func=func,
          start_point=np.zeros_like(minima),
          expected_argmin=minima,
      )
  
imports: import numpy
  import tensorflow.compat.v2
  import tf_quant_finance
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 19 for calling the ConjugateGradientTest obj's underlying member method code with example usage: obj.test_multiple_functions() without return types