code: def test_csrtodok():
      h = [[5, 7, 5], [2, 1, 3], [0, 1, 1, 3], [3, 4]]
      g = [[12, 5, 4], [2, 4, 2], [0, 1, 2, 3], [3, 7]]
      i = [[1, 3, 12], [0, 2, 4], [0, 2, 3], [2, 5]]
      j = [[11, 15, 12, 15], [2, 4, 1, 2], [0, 1, 1, 2, 3, 4], [5, 8]]
      k = [[1, 3], [2, 1], [0, 1, 1, 2], [3, 3]]
      m = _csrtodok(h)
      assert isinstance(m, SparseMatrix)
      assert m == SparseMatrix(3, 4, {(0, 2): 5, (2, 1): 7, (2, 3): 5})
      assert _csrtodok(g) == SparseMatrix(
          3, 7, {(0, 2): 12, (1, 4): 5, (2, 2): 4}
      )
      assert _csrtodok(i) == SparseMatrix(
          [[1, 0, 3, 0, 0], [0, 0, 0, 0, 12]]
      )
      assert _csrtodok(j) == SparseMatrix(
          5, 8, {(0, 2): 11, (2, 4): 15, (3, 1): 12, (4, 2): 15}
      )
      assert _csrtodok(k) == SparseMatrix(3, 3, {(0, 2): 1, (2, 1): 3})
  
imports: from sympy.matrices.sparsetools import _doktocsr, _csrtodok, banded
  from sympy.matrices.dense import Matrix, eye, ones, zeros
  from sympy.matrices import SparseMatrix
  from sympy.testing.pytest import raises
label_desc: Use image node_id 2 for calling a global function with example usage: test_csrtodok() without return types