code: def test_var_dims(self):
      self.assertEqual(
          parse("var * bool", self.sym),
          ct.DataShape(ct.Var(), ct.bool_),
      )
      self.assertEqual(
          parse("var * var * bool", self.sym),
          ct.DataShape(ct.Var(), ct.Var(), ct.bool_),
      )
      self.assertEqual(
          parse("M * 5 * var * bool", self.sym),
          ct.DataShape(
              ct.TypeVar("M"), ct.Fixed(5), ct.Var(), ct.bool_
          ),
      )
  
imports: from __future__ import absolute_import, division, print_function
  import unittest
  import pytest
  from datashader import datashape
  from datashader.datashape.util.testing import assert_dshape_equal
  from datashader.datashape.parser import parse
  from datashader.datashape import coretypes
  from datashader.datashape import DataShapeSyntaxError
label_desc: Use image node_id 4 for calling the TestDataShapeParserDims obj's underlying member method code with example usage: obj.test_var_dims() without return types