code: def test_deltasummation_trivial():
      assert ds(x, (j, 1, 0)) == 0
      assert ds(x, (j, 1, 3)) == 3 * x
      assert ds(x + y, (j, 1, 3)) == 3 * (x + y)
      assert ds(x * y, (j, 1, 3)) == 3 * x * y
      assert ds(KD(i, j), (k, 1, 3)) == 3 * KD(i, j)
      assert ds(x * KD(i, j), (k, 1, 3)) == 3 * x * KD(i, j)
      assert ds(x * y * KD(i, j), (k, 1, 3)) == 3 * x * y * KD(i, j)
  
imports: from sympy.concrete import Sum
  from sympy.concrete.delta import deltaproduct, deltasummation, _extract_delta
  from sympy.core import Eq, S, symbols, oo
  from sympy.functions import KroneckerDelta, Piecewise, piecewise_fold
  from sympy.logic import And
  from sympy.testing.pytest import raises
label_desc: Use image node_id 13 for calling a global function with example usage: test_deltasummation_trivial() without return types