code: def __init__(self):
      self.nfev = 0
      self.ngev = 0
      self.nhev = 0
  
imports: import pytest
  import numpy
  from numpy.testing import TestCase, assert_array_almost_equal, assert_array_equal, assert_, assert_allclose, assert_equal
  from scipy.sparse import csr_matrix
  from scipy.sparse.linalg import LinearOperator
  from scipy.optimize._differentiable_functions import ScalarFunction, VectorFunction, LinearVectorFunction, IdentityVectorFunction
  from scipy.optimize._hessian_update_strategy import BFGS
label_desc: Use image node_id 1 to create a new ExScalarFunction object  with example: obj = ExScalarFunction()