code: def test_var_vals_empty(self):
      assert ShapeTracker.from_shape((3, 4, 5)).var_vals == {}
  
imports: import unittest
  from tinygrad.shape.shapetracker import ShapeTracker, View
  from tinygrad.shape.symbolic import Variable, NumNode
  from tinygrad.tensor import Tensor
label_desc: Use image node_id 1 for calling the TestSymbolicVarVals obj's underlying member method code with example usage: obj.test_var_vals_empty() without return types