code: def test_as_symbolic():
      res = as_symbolic(None)
      assert res is NoneConst
  
      res = as_symbolic(slice(iscalar()))
      assert res.owner.op == make_slice
  
      res = as_symbolic(slice(1, 2))
      assert isinstance(res, SliceConstant)
  
file_path: pytensor/tests/tensor/test_type_other.py
imports: import pytensor
  from pytensor import as_symbolic
  from pytensor.graph.basic import Constant
  from pytensor.tensor.math import argmax
  from pytensor.tensor.type import iscalar, vector
  from pytensor.tensor.type_other import MakeSlice, NoneConst, NoneTypeT, SliceConstant, SliceType, make_slice
label_desc: Use image node_id 4 for calling a global function with example usage: test_as_symbolic() without return types