code: def jac(self, x):
      self.njev += 1
      return np.array(
          [[4 * x[0] - 1, 4 * x[1]], [12 * x[0] ** 2 - 3, 8 * x[1]]],
          dtype=x.dtype,
      )
  
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 import rosen, rosen_der, rosen_hess
  from scipy.optimize._hessian_update_strategy import BFGS
label_desc: Use image node_id 3 for calling the ExVectorialFunction obj's underlying member method code with example usage: obj.jac(x) and returns: np