code: def test_finite_diff():
      assert finite_diff(x**2 + 2 * x + 1, x) == 2 * x + 3
      assert (
          finite_diff(y**3 + 2 * y**2 + 3 * y + 5, y)
          == 3 * y**2 + 7 * y + 6
      )
      assert finite_diff(z**2 - 2 * z + 3, z) == 2 * z - 1
      assert finite_diff(w**2 + 3 * w - 2, w) == 2 * w + 4
      assert finite_diff(sin(x), x, pi / 6) == -sin(x) + sin(x + pi / 6)
      assert finite_diff(cos(y), y, pi / 3) == -cos(y) + cos(y + pi / 3)
      assert finite_diff(x**2 - 2 * x + 3, x, 2) == 4 * x
      assert finite_diff(n**2 - 2 * n + 3, n, 3) == 6 * n + 3
  
file_path: sympy/sympy/series/tests/test_kauers.py
imports: from sympy.series.kauers import finite_diff
  from sympy.series.kauers import finite_diff_kauers
  from sympy.abc import x, y, z, m, n, w
  from sympy.core.numbers import pi
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.concrete.summations import Sum
label_desc: Use image node_id 1 for calling a global function with example usage: test_finite_diff() without return types