code: def test_dtypes():
      def f(x):
          return 2 * x
  
      desired = np.array([[2, 0], [0, 2]])
      assert_allclose(approx_fprime(np.array([1, 2]), f), desired)
      assert_allclose(approx_fprime(np.array([1.0, 2.0]), f), desired)
      assert_allclose(
          approx_fprime(np.array([1.0 + 0j, 2.0 + 0j]), f), desired
      )
  
imports: import numpy
  from numpy.testing import assert_allclose, assert_almost_equal
  import statsmodels.api
  from statsmodels.tools import numdiff
  from statsmodels.tools.numdiff import approx_fprime, approx_fprime_cs, approx_hess_cs, _approx_fprime_scalar, _approx_fprime_cs_scalar
label_desc: Use image node_id 5 for calling a global function with example usage: test_dtypes() and returns: unknown