code: def test_ndim():
      cs = CoordinateSystem("xy")
      assert cs.ndim == 2
      cs = CoordinateSystem("ijk")
      assert cs.ndim == 3
  
imports: from types import SimpleNamespace
  import numpy
  import pytest
  from ..coordinate_system import CoordinateSystem, CoordinateSystemError, CoordSysMaker, CoordSysMakerError, is_coordsys, is_coordsys_maker, product, safe_dtype
label_desc: Use image node_id 4 for calling a global function with example usage: test_ndim() without return types